Add cd auto-listing and extract helper to default zshrc

Port cd() wrapper (auto eza listing on directory change) and
extract() function (universal archive extraction) from active
user config into moonarch defaults.

defaults/shell/zshrc

@@ -65,6 +65,15 @@ if [ -d "$HOME/.local/bin" ]; then
     PATH="$HOME/.local/bin:$PATH"
 fi
 
+# --- cd with auto-listing ---
+function cd() {
+    new_directory="$*";
+    if [ $# -eq 0 ]; then
+        new_directory=${HOME};
+    fi;
+    builtin cd "${new_directory}" && eza -lF --icons --color=always --group-directories-first
+}
+
 # --- Key bindings ---
 bindkey "^[[3~"   delete-char
 bindkey "^[[H"    beginning-of-line
@@ -82,6 +91,30 @@ alias l='eza -F --icons --color=always --group-directories-first'
 alias vim='nvim'
 alias uninstall='sudo pacman -Rsn'
 
+# --- Extract archives ---
+function extract() {
+    if [ -f "$1" ]; then
+        case "$1" in
+            *.tar.bz2)   tar xjvf "$1"   ;;
+            *.tar.gz)    tar xzvf "$1"   ;;
+            *.tar.xz)    tar xvf "$1"    ;;
+            *.bz2)       bzip2 -d "$1"   ;;
+            *.rar)       unrar2dir "$1"  ;;
+            *.gz)        gunzip "$1"     ;;
+            *.tar)       tar xf "$1"     ;;
+            *.tbz2)      tar xjf "$1"    ;;
+            *.tgz)       tar xzf "$1"    ;;
+            *.zip)       unzip2dir "$1"  ;;
+            *.Z)         uncompress "$1" ;;
+            *.7z)        7z x "$1"       ;;
+            *.ace)       unace x "$1"    ;;
+            *)           echo "'$1' cannot be extracted via extract()" ;;
+        esac
+    else
+        echo "'$1' is not a valid file"
+    fi
+}
+
 # --- FZF ---
 if command -v fzf &>/dev/null; then
     eval "$(fzf --zsh)"