feat: disable JIT native compilation by default

Newcomers may find background JIT compilation confusing as it causes
unpredictable sluggishness. Disable it by default and add comments
guiding users on how to re-enable it for extra performance.

Update README to reflect the new behavior.

init.el

@@ -1,7 +1,7 @@
 ;;; init.el --- Emacs-Kick --- A feature rich Emacs config for (neo)vi(m)mers -*- lexical-binding: t; -*-
 ;; Author: Rahul Martim Juliato
 
-;; Version: 0.3.3
+;; Version: 0.3.4
 ;; Package-Requires: ((emacs "30.1"))
 ;; License: GPL-2.0-or-later
 
@@ -105,6 +105,20 @@
 ;; Set the maximum output size for reading process output, allowing for larger data transfers.
 (setq read-process-output-max (* 1024 1024 4))
 
+;; Disable JIT native compilation during normal usage.
+;; All native compilation is handled upfront during installation
+;; (e.g., via `ek-reinstall.sh' or `ek/first-install').
+;; This prevents Emacs from compiling packages in the background
+;; while you're working, which can cause occasional stutters.
+(setq native-comp-jit-compilation nil)
+;; If you find Emacs slow for your usage, JIT native compilation increases
+;; performance dramatically.  Its default behavior, however, can be confusing
+;; for newcomers since it compiles things in the background unpredictably.
+;; To enable it, change the value above to `t'.  After that, every time you
+;; first use a feature, JIT will compile it in the background, so expect
+;; things to be sluggish for a bit.  Once everything is compiled, it's
+;; speed all the way.
+
 ;; Do I really need a speedy startup?
 ;; Well, this config launches Emacs in about ~0.3 seconds,
 ;; which, in modern terms, is a miracle considering how fast it starts