Make it clear that obstacles don't affect pathfinding

doc/classes/NavigationObstacle2D.xml

@@ -5,7 +5,7 @@
 	</brief_description>
 	<description>
 		2D Obstacle used in navigation for collision avoidance. The obstacle needs navigation data to work correctly. [NavigationObstacle2D] is physics safe.
-		[b]Note:[/b] Obstacles are intended as a last resort option for constantly moving objects that cannot be (re)baked to a navigation mesh efficiently.
+		Obstacles [b]don't[/b] change the resulting path from the pathfinding, they only affect the navigation agent movement in a radius. Therefore, using obstacles for the static walls in your level won't work because those walls don't exist in the pathfinding. The navigation agent will be pushed in a semi-random direction away while moving inside that radius. Obstacles are intended as a last resort option for constantly moving objects that cannot be (re)baked to a navigation mesh efficiently.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/NavigationObstacle3D.xml

@@ -5,7 +5,7 @@
 	</brief_description>
 	<description>
 		3D Obstacle used in navigation for collision avoidance. The obstacle needs navigation data to work correctly. [NavigationObstacle3D] is physics safe.
-		[b]Note:[/b] Obstacles are intended as a last resort option for constantly moving objects that cannot be (re)baked to a navigation mesh efficiently.
+		Obstacles [b]don't[/b] change the resulting path from the pathfinding, they only affect the navigation agent movement in a radius. Therefore, using obstacles for the static walls in your level won't work because those walls don't exist in the pathfinding. The navigation agent will be pushed in a semi-random direction away while moving inside that radius. Obstacles are intended as a last resort option for constantly moving objects that cannot be (re)baked to a navigation mesh efficiently.
 	</description>
 	<tutorials>
 	</tutorials>