generate rst doc pages for command line tools (#27530)

* let generate_man also gen rst pages for cli tools
* make template-file, output-dir, output format cli options for generate_man
* update main Makefile to use generate_man.py for docs (man pages and rst)
* update vault docs that use :option:
* Edits based on
6e34ea6242 and
a3afc78535

* add a optparse 'desc' to lib/ansible/cli/config.py 

  The man page needs a short desc for the 'NAME' field
  which it gets from the option parse 'desc' value.

  Fixes building ansible-config man page.

* add trim_docstring from pep257 to generate_man

  use pep258 docstring trim function to fix up any indention
  weirdness inherit to doc strings (ie, lines other than
  first line being indented.

* Add refs to cli command actions

To reference ansible-vaults --vault-id option, use:

:option:`The link text here <ansible-vault --vault-id>`

or:

:option:`--vault-id <ansible-vault --vault-id>`

To reference ansible-vault's 'encrypt' action, use:

:ref:`The link text here <ansible_vault_encrypt>`

or most of the time:

:ref:`ansible-vault encrypt <ansible_vault_encrypt>`

Makefile

@@ -29,6 +29,7 @@ ASCII2HTMLMAN = a2x -L -D docs/html/man/ -d manpage -f xhtml
 else
 ASCII2MAN = @echo "ERROR: AsciiDoc 'a2x' command is not installed but is required to build $(MANPAGES)" && exit 1
 endif
+GENERATE_CLI = docs/bin/generate_man.py
 
 PYTHON=python
 SITELIB = $(shell $(PYTHON) -c "from distutils.sysconfig import get_python_lib; print get_python_lib()")
@@ -343,8 +344,9 @@ webdocs:
 
 .PHONY: generate_asciidoc
 generate_asciidoc: lib/ansible/cli/*.py
-	mkdir -p ./docs/man/man1/
-	PYTHONPATH=./lib ./docs/bin/generate_man.py
+	mkdir -p ./docs/man/man1/ ; \
+	PYTHONPATH=./lib $(GENERATE_CLI) --template-file=docs/templates/man.j2 --output-dir=docs/man/man1/ --output-format man lib/ansible/cli/*.py
+
 
 docs: generate_asciidoc
 	make $(MANPAGES)