Add rst code-block snippet

When editing `rst` filetypes for longer periods airline started
producing errors when attempting to count the number of words in the
document, so disable this feature.

UltiSnips/rst.snippets

@@ -47,3 +47,9 @@ snippet warning "warning admonition"
 .. warning::
 	$0
 endsnippet
+
+snippet code "code-block"
+.. code-block:: ${1:lang}
+
+	$0
+endsnippet

vimrc

@@ -28,6 +28,7 @@ set packpath+=~/.config/work
 Pack 'vim-airline/vim-airline'
 let g:airline#extensions#branch#enabled = 0
 let g:airline#extensions#hunks#enabled = 0
+let g:airline#extensions#wordcount#enabled = 0
 for s:setting in ['left_sep', 'right_sep', 'section_error', 'section_warning']
   exec 'let g:airline_'.s:setting.' = ""'
 endfor