Update README.md (#996)

Author: hbin

Diff for: README.md

@@ -281,7 +281,7 @@ Keybinding         | Description
 <kbd>C-x M-g</kbd> | Open Magit's popup of popups.
 <kbd>M-Z</kbd>     | Zap up to char.
 <kbd>C-=</kbd>     | Run `expand-region` (incremental text selection).
-<kbd>C-a</kbd>     | Run `prelude-move-beginning-of-line`. Read [this](http://emacsredux.com/blog/2013/05/22/smarter-navigation-to-the-beginning-of-a-line/) for details.
+<kbd>C-a</kbd>     | Run `crux-move-beginning-of-line`. Read [this](http://emacsredux.com/blog/2013/05/22/smarter-navigation-to-the-beginning-of-a-line/) for details.
 
 #### Prelude Mode