[Emacs] Add doc, config, reorganize code, update org-mode sources

There no longer is a big code block at the beginning of the basic
configuration paragraph. It is now all documented.

Dired is also much more customized, with its configuration fully
documented.

Parinfer and Evil-surround were also added to the list

Custom PATH was removed since it caused some serious issues with Emacs
not finding required binaries. It seems this was only needed at a
certain point in my Spacemacs config, and it is no longer needed in
either Spacemacs nor my current config.

Some preliminary work with EXWM has been done, though I am still not
sure if I’ll ever use it as my main WM (I’m currently also taking a
look at StumpWM).

Bufler was added to my packages for managing my buffers.

Org-mode moved `org-plus-contrib' out of the main repo, and it is now
a separate package, `org-contrib'. I now also follow the git version
of org-mode (it is no longer managed by my system’s package manager).

.config/tmux

@@ -1 +1 @@
-Subproject commit f4fc2730cf1a2ae26ebf3707548945a73cd74ff1
+Subproject commit 1f91646af104ed423054a1dd47a3b8c7ae69cfbc