Add config for mackup

- ignore apps whose config files are in the `dotfiles` repo
  (see: https://gitlab.webartifex.biz/alexander/dotfiles)
- include various (config) files that should not be public:
  + Cisco's AnyConnect
  + history files for `bash`, `less`, `python`, `psql`, `tig`, and `zsh`
  + Nautilus' bookmarks
  + SSH config & known hosts

.mackup.cfg

@@ -0,0 +1,24 @@
+[storage]
+engine = file_system
+path = nextcloud/getraenkemarkt
+directory = mackup
+
+[applications_to_ignore]
+
+# Do not sync configuration files that are kept in `git`
+# See: https://gitlab.webartifex.biz/alexander/dotfiles
+bash
+bat
+git
+flameshot
+mackup
+p10k
+pgsql
+poetry
+ssh
+vim
+wget
+zsh
+
+# Somehow, libreoffice cannot start with some other machine's configuration
+libreoffice