New feat.: localize new note's front matter / theme selection * Localize new note's front matter * Theme selection: A theme is an interchangeable set of configuration file variables. Tp-Note is shipped with two scheme: `default`, `zettel` (for Zettelkasten, experimental). The user can select a scheme with: * the command line option `--scheme SCHEME_NAME`, * environment variable `TPNOTE_SCHEME` or * the configuration file variable `arg_default.scheme`. * The command line option: `--force-lang='-'` is replaced with `--force-lang=''`