Fix Unicode URL link tags to render correctly.

Change incorrect `[/code]` closing tags to `[/url]` tags.

The `url` tags for the links to the Unicode code points information use `[/code]` rather than `[/url]` to close them.

This results in the links being rendered incorrectly in the IDE--the entire rest of the documentation for each method gets turned into a giant underlined link.

This issue was introduced in a2271ba3bd.

(cherry picked from commit b85688ac7d)

doc/classes/String.xml

@@ -214,7 +214,7 @@
 			<return type="int" />
 			<argument index="0" name="to" type="String" />
 			<description>
-				Performs a case-sensitive comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/code] of each string, which roughly matches the alphabetical order.
+				Performs a case-sensitive comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/url] of each string, which roughly matches the alphabetical order.
 				[b]Behavior with different string lengths:[/b] Returns [code]1[/code] if the "base" string is longer than the [code]to[/code] string or [code]-1[/code] if the "base" string is shorter than the [code]to[/code] string. Keep in mind this length is determined by the number of Unicode codepoints, [i]not[/i] the actual visible characters.
 				[b]Behavior with empty strings:[/b] Returns [code]-1[/code] if the "base" string is empty, [code]1[/code] if the [code]to[/code] string is empty or [code]0[/code] if both strings are empty.
 				To get a boolean result from a string comparison, use the [code]==[/code] operator instead. See also [method nocasecmp_to].
@@ -505,7 +505,7 @@
 			<return type="int" />
 			<argument index="0" name="to" type="String" />
 			<description>
-				Performs a case-insensitive [i]natural order[/i] comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/code] of each string, which roughly matches the alphabetical order. Internally, lowercase characters will be converted to uppercase during the comparison.
+				Performs a case-insensitive [i]natural order[/i] comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/url] of each string, which roughly matches the alphabetical order. Internally, lowercase characters will be converted to uppercase during the comparison.
 				When used for sorting, natural order comparison will order suites of numbers as expected by most people. If you sort the numbers from 1 to 10 using natural order, you will get [code][1, 2, 3, ...][/code] instead of [code][1, 10, 2, 3, ...][/code].
 				[b]Behavior with different string lengths:[/b] Returns [code]1[/code] if the "base" string is longer than the [code]to[/code] string or [code]-1[/code] if the "base" string is shorter than the [code]to[/code] string. Keep in mind this length is determined by the number of Unicode codepoints, [i]not[/i] the actual visible characters.
 				[b]Behavior with empty strings:[/b] Returns [code]-1[/code] if the "base" string is empty, [code]1[/code] if the [code]to[/code] string is empty or [code]0[/code] if both strings are empty.
@@ -516,7 +516,7 @@
 			<return type="int" />
 			<argument index="0" name="to" type="String" />
 			<description>
-				Performs a case-insensitive comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/code] of each string, which roughly matches the alphabetical order. Internally, lowercase characters will be converted to uppercase during the comparison.
+				Performs a case-insensitive comparison to another string. Returns [code]-1[/code] if less than, [code]1[/code] if greater than, or [code]0[/code] if equal. "less than" or "greater than" are determined by the [url=https://en.wikipedia.org/wiki/List_of_Unicode_characters]Unicode code points[/url] of each string, which roughly matches the alphabetical order. Internally, lowercase characters will be converted to uppercase during the comparison.
 				[b]Behavior with different string lengths:[/b] Returns [code]1[/code] if the "base" string is longer than the [code]to[/code] string or [code]-1[/code] if the "base" string is shorter than the [code]to[/code] string. Keep in mind this length is determined by the number of Unicode codepoints, [i]not[/i] the actual visible characters.
 				[b]Behavior with empty strings:[/b] Returns [code]-1[/code] if the "base" string is empty, [code]1[/code] if the [code]to[/code] string is empty or [code]0[/code] if both strings are empty.
 				To get a boolean result from a string comparison, use the [code]==[/code] operator instead. See also [method casecmp_to].