Document render/update objects (#565)

* Document objects related code.
  * Including render/update objects code
* Various renamings

docs/actors/actors.md

@@ -30,7 +30,7 @@ void actor_name(Camera, Mat4, actor) {
 ```
 Check actor_types.h for a full list of options. You can create a new actor struct for your actor and customize it or use a predefined one. All actor structs must retain the same size. Generally, the types in the struct may be modified so long as `type` and `flags` stay the same as those are used elsewhere.
 
-See `update_obj_railroad_crossing` for an example of how a timer may be setup and used.   
+See `update_actor_railroad_crossing` for an example of how a timer may be setup and used.   
 
 Audio may be activated using the following method:
 @ref func_800C98B8

docs/basics/controlflow.md

@@ -89,7 +89,7 @@ Object related code resides in
 |file|desc|
 |---|---|
 |[code_80057C60](@ref code_80057C60.c)|Objects|
-|[code_80071F00](@ref code_80071F00.c)|Objects|
+|[update_objects](@ref update_objects.c)|Objects|
 |[code_80086E70](@ref code_80086E70.c)|Objects|
 
 Documentation of the specifics still in-progress. See [actors](actorsmenu.html) for more information.
@@ -114,7 +114,7 @@ Course related code resides in
 ## UI & Other 2D Screen data
 |file|desc|
 |---|---|
-|[hud_renderer](@ref hud_renderer.c)|ItemWindows|
+|[render_objects](@ref render_objects.c)|ItemWindows|
 
 ## Engine
 |file|desc|