feat(shell): add bash-style history expansions and interactive keybindings

- Replicate bash bang-operations (!^, !*, !string, etc.) via abbreviations
- Add Ctrl+G for previous path head insertion
- Add Ctrl+F for interactive history substitution
- Add Ctrl+Alt+U to quickly replace command tokens
- Update README documentation for all new features

functions/__insert_previous_path_head.fish

@@ -0,0 +1,11 @@
+function __insert_previous_path_head
+    # Get the last command tokens
+    set -l tokens (string split -n " " -- $history[1])
+    
+    # If there are tokens, take the last one and strip the 'tail'
+    if set -q tokens[-1]
+        set -l path_head (dirname -- $tokens[-1])
+        # Insert it into the current command line
+        commandline -i -- $path_head
+    end
+end