Add new Renderers page

Adds a new page which gives a summary of the three renderers. This page briefly
describes the renderers, gives some guidance on how to choose a renderer. It also
contains a comparison table between the renderers.
Adds an entry in the FAQ which links to this new page.
Adds a note about subsurface scattering limitations to the Standard Material page.
Adjusts some other pages which had incorrect information.

about/faq.rst

@@ -393,6 +393,11 @@ Some new versions are safer to upgrade to than others. In general, whether you
 should upgrade depends on your project's circumstances. See
 :ref:`doc_release_policy_should_i_upgrade_my_project` for more information.
 
+Should I use the Forward+, Mobile, or Compatibility renderer?
+-------------------------------------------------------------
+
+You can find a detailed comparison of the renderers in :ref:`doc_renderers`.
+
 I would like to contribute! How can I get started?
 --------------------------------------------------
 

about/list_of_features.rst

@@ -108,6 +108,8 @@ Rendering
   advanced graphics backend, suited for low-end desktop and mobile platforms.
   Used by default on the web platform.
 
+See :ref:`doc_renderers` for a detailed comparison of the rendering methods.
+
 2D graphics
 -----------
 
@@ -279,7 +281,8 @@ Rendering
   rendered with clustered forward optimizations to decrease their individual cost.
   Clustered rendering also lifts any limits on the number of reflection probes that can be used on a mesh.
 - When using the Forward Mobile backend, up to 8 reflection probes can be displayed per mesh
-  resource.
+  resource. When using the Compatibility renderer, up to 2 reflection probes can
+  be displayed per mesh resource.
 
 **Decals:**