feat(.vimrc): activate file type plugins

I found that autoindention didn't work without this setting for e.g.
 automatically indended sections after a function header.
Apparently one can choose here to limit the filetype-based features on
 indentions by only specifying "filetype indent on".
In contrast using "filetype plugin indent on" comes also with additional
 features like highlighting of language specific keywords.
Althought having such things implicitly makes a clean understanding
 difficult, I still consider them important for an efficient experience
 in vim.
Therefore I'll keep them and if necessary dive into them
 (e.g. in case of conflicts with own manual settings)

.vimrc

@@ -3,7 +3,7 @@ packadd vim-fugitive
 " }}}
 
 " Settings {{{
-filetype on
+filetype plugin indent on
 syntax on
 
 " Let's save undo info!