README: Explain repo structure and my system/tools

- Add a description of the repository that explains shortly how the repo
  is structured and what systems/tools I use.
- Go into more detail in the installation section
- Add links for reference

README.md

@@ -1,6 +1,43 @@
 # My dotfiles
 
+This is a collection of the configuration files and scripts I use for various
+tools and environments.
+
+Although some files support macOS, most of them assume that they are used on a
+GNU/Linux system. The systems I use include an Artix, a Manjaro and an Ubuntu
+installation. All of them running i3wm and the arch-based systems without a DE.
+I use [my fork][1] of [st][2] as terminal, [zsh][3] as shell and [neovim][4] as
+text editor.
+
+The repository mimics my `$HOME`, trying to conform to the [XDG Base Directory
+Specification][5] as close as possible. An exception is `etc/ -> /etc/`, as well
+as `meta/` and some other files in the root of the repository (e.g. this README
+or the LICENSE) which are not in my `$HOME`.
+
+The most interesting files are probably in [.config/zsh][6] and
+[.config/vim][7].
+
 ## Installation
+
+The repository content can be installed via [dotbot][8]. All existing files
+which would be overridden are first packed into an archive for backup (see
+[meta/archive][9]) and then dotbot places symlinks in the appropriate places for
+the different files and folders in this repository.
+
+To start the installation run:
+
 ```sh
 $ ./meta/install
 ```
+
+<!--- Links -->
+
+[1]: https://github.com/druckdev/st
+[2]: https://st.suckless.org/
+[3]: https://www.zsh.org/
+[4]: https://github.com/neovim/neovim
+[5]: https://wiki.archlinux.org/title/XDG_Base_Directory
+[6]: .config/zsh
+[7]: .config/vim
+[8]: https://github.com/anishathalye/dotbot
+[9]: meta/archive