update(README): added post editor shortcuts

Author: tmpmachine

README.md

@@ -9,8 +9,20 @@ Blog post (early release) : https://xmlexpr.blogspot.com/2024/01/blogger-dashboa
 3. Click **Load unpacked**, pick the folder where you put this repository files on point 1.
 
 # Features
-1. Notification on template HTML update. Auto close in 2 seconds.
-2. Display widget ID below gadget item in Layout editor.
+1. Post editor keyboard shortcuts.
+2. Notification on template HTML update. Auto close in 2 seconds.
+3. Display widget ID below gadget item in Layout editor.
 
-# WIP
-- Keyboard shortcuts for post editor.
+## Post Editor Keyboard Shortcuts
+- Ctrl + S : Update post (for drafts)
+- Ctrl + M : Add yellow text background to selection (useful for custom text mark).
+- Ctrl + 5 : Format Paragraph (`<p>`).
+- Ctrl + Space : Remove formatting on selection.
+
+## Template Save Status Notification
+The current notification is somewhat of a workaround. Can't find easy way to detect failed status when saving template.
+
+Message | Condition
+--- | ---
+Template updated | No errors when saving template.
+Check for errors | Either it takes too long to receive the success status, or there's an error when saving the template.