ajout de Sheebr + support de shutdown + auto install kernel

rootfs overrides/chibrax/sleep.js

@@ -0,0 +1,9 @@
+async function mSleep(ms) {
+    return new Promise(resolve => setTimeout(resolve, ms))
+}
+
+async function sleep(s) {
+    return mSleep(s * 1000)
+}
+
+module.exports = { mSleep, sleep }