Cleanup: code-comments, use doxygen formatting & spelling corrections

Also move some function doc-strings from the implementation
to their declarations.

scripts/templates_py/ui_list.py

@@ -31,13 +31,14 @@ class MESH_UL_mylist(bpy.types.UIList):
         # This function gets the collection property (as the usual tuple (data, propname)), and must return two lists:
         # * The first one is for filtering, it must contain 32bit integers were self.bitflag_filter_item marks the
         #   matching item as filtered (i.e. to be shown). The upper 16 bits (including self.bitflag_filter_item) are
-        #   reseverd for internal use, the lower 16 bits are free for custom use. Here we use the first bit to mark
+        #   reserved for internal use, the lower 16 bits are free for custom use. Here we use the first bit to mark
         #   VGROUP_EMPTY.
         # * The second one is for reordering, it must return a list containing the new indices of the items (which
         #   gives us a mapping org_idx -> new_idx).
-        # Please note that the default UI_UL_list defines helper functions for common tasks (see its doc for more info).
-        # If you do not make filtering and/or ordering, return empty list(s) (this will be more efficient than
-        # returning full lists doing nothing!).
+        # Please note that the default `UI_UL_list` defines helper functions for common tasks
+        # (see its doc for more info).
+        # If you do not make filtering and/or ordering, return empty list(s)
+        # (this will be more efficient than returning full lists doing nothing!).
 
         # Default return values.
         flt_flags = []