Fixes to the documentation build (#15356)

* Could only have one alias before.  Subsequent aliases overrode the
  previous ones.  Now multiple aliases work.
* Fix BLACKLISTED_MODULES.   Previously, modules were listed in the
  generated documentation despite being blacklisted
* Deprecated modules form extras were showing the (E) tag and not the
  (D) tag. Reversed that now (Probably not necessary to also show the
  E tag).
* Sort the deprecated modules alphabetically in the Category docs as
  well as the list of all modules
* Optimization: Previously rendered the modules to rst twice once in all
  group and once in individual categories.  Fixed to only render them
  once.
* Add fireball to blacklist and remove async_status (as people need to
  use that).

lib/ansible/utils/module_docs.py

@@ -37,9 +37,11 @@ except ImportError:
     display = Display()
 
 # modules that are ok that they do not have documentation strings
-BLACKLIST_MODULES = [
-   'async_wrapper', 'accelerate', 'async_status'
-]
+BLACKLIST_MODULES = frozenset((
+   'async_wrapper',
+   'accelerate',
+   'fireball',
+))
 
 def get_docstring(filename, verbose=False):
     """