Improve dictionary description

I improved dictionary description to ad some real life examples and expand on it a little bit so person who never seen dictionary can understand it better seeing them for a first time here. 
I also added note about the way to compare dictionaries  as it can catch people of guard because common assumption is that it works the same as comparing Arrays when it does not.

doc/classes/Dictionary.xml

@@ -4,16 +4,61 @@
 		Dictionary type.
 	</brief_description>
 	<description>
-		Dictionary type. Associative container which contains values referenced by unique keys. Dictionaries are always passed by reference.
+		Dictionary type. Associative container which contains values referenced by unique keys. Dictionary are composed of pairs of keys (which must be unique) and values. You can define a dictionary by placing a comma separated list of [code]key: value[/code] pairs in curly braces [code]{}[/code].
 		Erasing elements while iterating over them [b]is not supported[/b].
 		Creating a dictionary:
 		[codeblock]
-		var d = {4: 5, "A key": "A value", 28: [1, 2, 3]}
+		var my_dir = {} # Creates an empty dictionary.
+		var points_dir = {"White": 50, "Yellow": 75, "Orange": 100}
+		var my_dir = {
+		    key1: value1,
+		    key2: value2,
+		    key3: value3,
+		}
+		[/codeblock]
+		You can access values of a dictionary by referencing appropriate key in above example [code]points_dir["White"][/code] would return value of 50.
+		[codeblock]
+		export(String, "White", "Yellow", "Orange") var my_color
+		var points_dir = {"White": 50, "Yellow": 75, "Orange": 100}
+		
+		func _ready():
+		    var points = points_dir[my_color]
+		[/codeblock]
+		In the above code [code]points[/code] will be assigned the value that is paired with the appropriate color selected in [code]my_color[/code].
+		Dictionaries can contain more complex data:
+		[codeblock]
+		my_dir = {"First Array": [1, 2, 3, 4]} # Assigns an Array to a String key.
 		[/codeblock]
 		To add a key to an existing dictionary, access it like an existing key and assign to it:
 		[codeblock]
-		d[4] = "hello"  # Add integer 4 as a key and assign the String "hello" as its value.
+		var points_dir = {"White": 50, "Yellow": 75, "Orange": 100}
-		d["Godot"] = 3.01  # Add String "Godot" as a key and assign the value 3.01 to it.
+		var points_dir["Blue"] = 150  # Add "Blue" as a key and assign 150 as its value.
+		[/codeblock]
+		Finally, dictionaries can contain different types of keys and values in the same dictionary:
+		[codeblock]
+		var my_dir = {"String Key": 5, 4: [1, 2, 3], 7: "Hello"} # This is a valid dictionary.
+		[/codeblock]
+		[b]Note:[/b] Unlike [Array]s you can't compare dictionaries directly:
+		[codeblock]
+		array1 = [1, 2, 3]
+		array2 = [1, 2, 3]
+		
+		func compare_arrays():
+		    print(array1 == array2) # Will print true. 
+		
+		dir1 = {"a": 1, "b": 2, "c": 3}
+		dir2 = {"a": 1, "b": 2, "c": 3}
+		
+		func compare_dictionaries():
+		    print(dir1 == dir2) # Will NOT print true.
+		[/codeblock]
+		You need to first calculate the dictionary's hash with [method hash] before you can compare them:
+		[codeblock]
+		dir1 = {"a": 1, "b": 2, "c": 3}
+		dir2 = {"a": 1, "b": 2, "c": 3}
+		
+		func compare_dictionaries():
+		    print(dir1.hash() == dir2.hash()) # Will print true.
 		[/codeblock]
 	</description>
 	<tutorials>