Add configuration for zsh

- Add ~/.zshrc
  + Configure on how the `history` works
  + Enable nicer `cd` and globbing behavior
  + Enable tab completion, and make them feel nicer
  + Enable VI mode and add some VI-like key bindings
- Add ~/.zlogout clearing the screen
- Add ~/.config/zsh/.zshrc and make it dispatch to ~/.zshrc
  to make `zsh` use the same configuration even on more
  recent Debian/Ubuntu machines that do not look for
  ~/.zshrc any more
- Ensure ~/.local/state/zsh/ exists

.config/zsh/.zshrc

@@ -0,0 +1,12 @@
+#!/bin/zsh
+
+# Failsafe: Dispatch to the real `zsh` config file in ~/
+#
+# `zsh` itself only reads `$ZDOTDIR`, which defaults to ~/,
+# and never looks into ~/.config/zsh on its own
+# => This file is dead code unless something sets `$ZDOTDIR`
+#    to this folder (e.g., a future Debian default;
+#    see Debian bug #1036290 for such a proposal)
+
+
+[ -f "$HOME/.zshrc" ] && . "$HOME/.zshrc"