fixed an error and added a relevant cheat

noticed it because of a comment at https://devhints.io/vim where this sheet is referenced

vim.md

@@ -301,7 +301,8 @@ Do these in visual mode.
 | <code>``</code> | Last jump                                          |
 | ---             | ---                                                |
 | `ma`            | Mark this cursor position as `a`                   |
-| `'a`            | Jump to cursor position `a`            |
+| <code>`a</code> | Jump to the cursor position `a`                    |
+| `'a`            | Jump to the beginning of the line with position `a`|
 {: .-shortcuts}
 
 ### Misc