As this includes 4 levels of headings, the tag that needs to be used is
:TOC@4:. Now every time one saves this file, the TOC is automatically
generated. There is an interesting feature from toc-org that enables
users to use org links or GitHub enabled
[links](https://github.com/snosov1/toc-org#use)
we should discuss how to use it because on one hand, having org links
makes it easier to read in emacs, while having GitHub links makes it
easier to read online.
- Use `~` marker to represent key bindings. The `~` and `=` markers are
equivalent in Emacs: `=` uses `org-verbatim verbatim` faces, while `~`
uses `org-code verbatim)`, but both `org-verbatim` and `org-code` is
inherited from `shadow` face. So we can use `~` marker for this purpose.
`~` marker is also displayed properly on Github, since it's part of
standard Emacs, so no web functionality is broken.
- Add org-kbd face for displaying key bindings.
- Update CHANGELOG.org: use the proper `~` marker for key bindings.
- Update VIMUSERS.org: use the proper `~` marker for key bindings.
