Clarify type-specific `lerp()` documentation

Clarifies that `lerp()` can be used for interpolation or extrapolation.
Links to the GlobalScope `lerp()` docs.

doc/classes/Color.xml

@@ -306,7 +306,9 @@
 			<param index="0" name="to" type="Color" />
 			<param index="1" name="weight" type="float" />
 			<description>
-				Returns the linear interpolation between this color's components and [param to]'s components. The interpolation factor [param weight] should be between 0.0 and 1.0 (inclusive). See also [method @GlobalScope.lerp].
+				Returns the linear interpolation between this color's components and [param to]'s components.
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 				[codeblocks]
 				[gdscript]
 				var red = Color(1.0, 0.0, 0.0)

doc/classes/Transform2D.xml

@@ -145,7 +145,8 @@
 			<param index="1" name="weight" type="float" />
 			<description>
 				Returns the result of the linear interpolation between this transform and [param xform] by the given [param weight].
-				The [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). Values outside this range are allowed and can be used to perform [i]extrapolation[/i] instead.
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 			</description>
 		</method>
 		<method name="inverse" qualifiers="const">

doc/classes/Transform3D.xml

@@ -72,7 +72,8 @@
 			<param index="1" name="weight" type="float" />
 			<description>
 				Returns the result of the linear interpolation between this transform and [param xform] by the given [param weight].
-				The [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). Values outside this range are allowed and can be used to perform [i]extrapolation[/i] instead.
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 			</description>
 		</method>
 		<method name="inverse" qualifiers="const">

doc/classes/Vector2.xml

@@ -263,7 +263,9 @@
 			<param index="0" name="to" type="Vector2" />
 			<param index="1" name="weight" type="float" />
 			<description>
-				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight]. [param weight] is on the range of [code]0.0[/code] to [code]1.0[/code], representing the amount of interpolation.
+				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight].
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 			</description>
 		</method>
 		<method name="limit_length" qualifiers="const" keywords="truncate">

doc/classes/Vector3.xml

@@ -232,7 +232,9 @@
 			<param index="0" name="to" type="Vector3" />
 			<param index="1" name="weight" type="float" />
 			<description>
-				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight]. [param weight] is on the range of [code]0.0[/code] to [code]1.0[/code], representing the amount of interpolation.
+				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight].
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 			</description>
 		</method>
 		<method name="limit_length" qualifiers="const" keywords="truncate">

doc/classes/Vector4.xml

@@ -181,7 +181,9 @@
 			<param index="0" name="to" type="Vector4" />
 			<param index="1" name="weight" type="float" />
 			<description>
-				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight]. [param weight] is on the range of [code]0.0[/code] to [code]1.0[/code], representing the amount of interpolation.
+				Returns the result of the linear interpolation between this vector and [param to] by amount [param weight].
+				To perform interpolation, [param weight] should be between [code]0.0[/code] and [code]1.0[/code] (inclusive). However, values outside this range are allowed and can be used to perform [i]extrapolation[/i]. If this is not desired, use [method @GlobalScope.clampf] to limit [param weight].
+				See also [method @GlobalScope.lerp].
 			</description>
 		</method>
 		<method name="max" qualifiers="const">