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/shell/aliases

@@ -12,9 +12,19 @@ forget() {  # the current history and restore $HISTFILE from disk
     if [ -n "$BASH_VERSION" ]; then
         history -c
         history -r
+    elif [ -n "$ZSH_VERSION" ]; then
+        local _histsize=$HISTSIZE
+        HISTSIZE=0  # because shrinking the list to 0 discards all entries
+        HISTSIZE=$_histsize
+        fc -R "$HISTFILE"
     fi
 }
 
+if [ -n "$ZSH_VERSION" ]; then
+    alias forget=' forget'  # Leading space => The invocation itself is forgotten
+fi
+
 
 
 alias grep='grep --exclude-dir=.git'
+

.config/zsh/.zshrc

@@ -0,0 +1,10 @@
+#!/bin/zsh
+
+# Load the real `zsh` config file in ~/
+#
+# Recent Debian/Ubuntu versions look for .zshrc
+# in ~/.config/zsh and no longer in ~/ which
+# is still the main location in many other distributions
+
+
+[ -f "$HOME/.zshrc" ] && . "$HOME/.zshrc"

.config/zsh/README.md

@@ -0,0 +1,3 @@
+# `zsh`-related Configurations
+
+This folder contains files that are sourced by `zsh`.