Unify similar method descriptions

Notably:

* `Pool*Array.size()` and `Array.size()`.
* Shared methods of `Transform2D` and `Transform`.
* Shared methods of `Vector2` and `Vector3`.

This reduces the Deja Vu when translating the class reference :)

doc/classes/PoolByteArray.xml

@@ -125,7 +125,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 		<method name="subarray">

doc/classes/PoolColorArray.xml

@@ -76,7 +76,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/PoolIntArray.xml

@@ -78,7 +78,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the array size.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/PoolRealArray.xml

@@ -78,7 +78,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/PoolStringArray.xml

@@ -84,7 +84,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/PoolVector2Array.xml

@@ -77,7 +77,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/PoolVector3Array.xml

@@ -76,7 +76,7 @@
 		<method name="size">
 			<return type="int" />
 			<description>
-				Returns the size of the array.
+				Returns the number of elements in the array.
 			</description>
 		</method>
 	</methods>

doc/classes/RayCast.xml

@@ -38,8 +38,7 @@
 		<method name="force_raycast_update">
 			<return type="void" />
 			<description>
-				Updates the collision information for the ray.
+				Updates the collision information for the ray. Use this method to update the collision information immediately instead of waiting for the next [code]_physics_process[/code] call, for example if the ray or its parent has changed state.
-				Use this method to update the collision information immediately instead of waiting for the next [code]_physics_process[/code] call, for example if the ray or its parent has changed state.
 				[b]Note:[/b] [code]enabled[/code] is not required for this to work.
 			</description>
 		</method>

doc/classes/Transform.xml

@@ -66,13 +66,13 @@
 			<argument index="0" name="transform" type="Transform" />
 			<argument index="1" name="weight" type="float" />
 			<description>
-				Interpolates the transform to other Transform by weight amount (on the range of 0.0 to 1.0).
+				Returns a transform interpolated between this transform and another by a given [code]weight[/code] (on the range of 0.0 to 1.0).
 			</description>
 		</method>
 		<method name="inverse">
 			<return type="Transform" />
 			<description>
-				Returns the inverse of the transform, under the assumption that the transformation is composed of rotation and translation (no scaling, use affine_inverse for transforms with scaling).
+				Returns the inverse of the transform, under the assumption that the transformation is composed of rotation and translation (no scaling, use [method affine_inverse] for transforms with scaling).
 			</description>
 		</method>
 		<method name="is_equal_approx">
@@ -95,7 +95,7 @@
 		<method name="orthonormalized">
 			<return type="Transform" />
 			<description>
-				Returns the transform with the basis orthogonal (90 degrees), and normalized axis vectors.
+				Returns the transform with the basis orthogonal (90 degrees), and normalized axis vectors (scale of 1 or -1).
 			</description>
 		</method>
 		<method name="rotated">

doc/classes/Vector2.xml

@@ -71,7 +71,7 @@
 		<method name="ceil">
 			<return type="Vector2" />
 			<description>
-				Returns the vector with all components rounded up (towards positive infinity).
+				Returns a new vector with all components rounded up (towards positive infinity).
 			</description>
 		</method>
 		<method name="clamped">
@@ -134,7 +134,7 @@
 		<method name="floor">
 			<return type="Vector2" />
 			<description>
-				Returns the vector with all components rounded down (towards negative infinity).
+				Returns a new vector with all components rounded down (towards negative infinity).
 			</description>
 		</method>
 		<method name="is_equal_approx">
@@ -183,7 +183,7 @@
 			<argument index="0" name="to" type="Vector2" />
 			<argument index="1" name="delta" type="float" />
 			<description>
-				Moves the vector toward [code]to[/code] by the fixed [code]delta[/code] amount.
+				Returns a new vector moved toward [code]to[/code] by the fixed [code]delta[/code] amount. Will not go past the final value.
 			</description>
 		</method>
 		<method name="normalized">
@@ -210,7 +210,7 @@
 			<return type="Vector2" />
 			<argument index="0" name="b" type="Vector2" />
 			<description>
-				Returns the vector projected onto the vector [code]b[/code].
+				Returns this vector projected onto the vector [code]b[/code].
 			</description>
 		</method>
 		<method name="reflect">
@@ -230,13 +230,13 @@
 		<method name="round">
 			<return type="Vector2" />
 			<description>
-				Returns the vector with all components rounded to the nearest integer, with halfway cases rounded away from zero.
+				Returns a new vector with all components rounded to the nearest integer, with halfway cases rounded away from zero.
 			</description>
 		</method>
 		<method name="sign">
 			<return type="Vector2" />
 			<description>
-				Returns the vector with each component set to one or negative one, depending on the signs of the components. If a component is zero, it returns positive one.
+				Returns a new vector with each component set to one or negative one, depending on the signs of the components. If a component is zero, it returns positive one.
 			</description>
 		</method>
 		<method name="slerp">

doc/classes/Vector3.xml

@@ -65,7 +65,7 @@
 			<argument index="2" name="post_b" type="Vector3" />
 			<argument index="3" name="weight" type="float" />
 			<description>
-				Performs a cubic interpolation between vectors [code]pre_a[/code], [code]a[/code], [code]b[/code], [code]post_b[/code] ([code]a[/code] is current), by the given amount [code]weight[/code]. [code]weight[/code] is on the range of 0.0 to 1.0, representing the amount of interpolation.
+				Performs a cubic interpolation between this vector and [code]b[/code] using [code]pre_a[/code] and [code]post_b[/code] as handles, and returns the result at position [code]weight[/code]. [code]weight[/code] is on the range of 0.0 to 1.0, representing the amount of interpolation.
 			</description>
 		</method>
 		<method name="direction_to">
@@ -170,7 +170,7 @@
 			<argument index="0" name="to" type="Vector3" />
 			<argument index="1" name="delta" type="float" />
 			<description>
-				Moves this vector toward [code]to[/code] by the fixed [code]delta[/code] amount.
+				Returns a new vector moved toward [code]to[/code] by the fixed [code]delta[/code] amount. Will not go past the final value.
 			</description>
 		</method>
 		<method name="normalized">
@@ -204,7 +204,7 @@
 			<return type="Vector3" />
 			<argument index="0" name="b" type="Vector3" />
 			<description>
-				Returns this vector projected onto another vector [code]b[/code].
+				Returns this vector projected onto the vector [code]b[/code].
 			</description>
 		</method>
 		<method name="reflect">
@@ -225,13 +225,13 @@
 		<method name="round">
 			<return type="Vector3" />
 			<description>
-				Returns this vector with all components rounded to the nearest integer, with halfway cases rounded away from zero.
+				Returns a new vector with all components rounded to the nearest integer, with halfway cases rounded away from zero.
 			</description>
 		</method>
 		<method name="sign">
 			<return type="Vector3" />
 			<description>
-				Returns a vector with each component set to one or negative one, depending on the signs of this vector's components. If a component is zero, it returns positive one.
+				Returns a new vector with each component set to one or negative one, depending on the signs of the components. If a component is zero, it returns positive one.
 			</description>
 		</method>
 		<method name="signed_angle_to">