Small documentation improvements

(cherry picked from commit 04b49264f2d752c32a4bb771367e78ca2f44b447)

doc/classes/Camera.xml

@@ -180,7 +180,7 @@
 			Perspective Projection (object's size on the screen becomes smaller when far away).
 		</constant>
 		<constant name="PROJECTION_ORTHOGONAL" value="1" enum="Projection">
-			Orthogonal Projection (objects remain the same size on the screen no matter how far away they are).
+			Orthogonal Projection (objects remain the same size on the screen no matter how far away they are; also known as orthographic projection).
 		</constant>
 		<constant name="KEEP_WIDTH" value="0" enum="KeepAspect">
 			Preserves the horizontal aspect ratio.

doc/classes/Path2D.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		Can have [PathFollow2D] child-nodes moving along the [Curve2D]. See [PathFollow2D] for more information on this usage.
+		Note that the path is considered as relative to the moved nodes (children of [PathFollow2D]) - usually the curve should start with a zero vector (0, 0).
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/Vector2.xml

@@ -216,7 +216,7 @@
 			<argument index="0" name="phi" type="float">
 			</argument>
 			<description>
-				Returns the vector rotated by [code]phi[/code] radians.
+				Returns the vector rotated by [code]phi[/code] radians. See also [method @GDScript.deg2rad].
 			</description>
 		</method>
 		<method name="round">