Fix up some tables

vim.md

@@ -45,6 +45,8 @@ Getting started
 
 #### Line
 
+| Shortcut     | Description                        |
+| ---          | ---                                |
 | `0` _(zero)_ | Start of line                      |
 | `^`          | Start of line _(after whitespace)_ |
 | `$`          | End of line                        |
@@ -52,6 +54,8 @@ Getting started
 
 #### Document
 
+| Shortcut | Description    |
+| ---      | ---            |
 | `gg`     | First line     |
 | `G`      | Last line      |
 | `:n`     | Go to line `n` |
@@ -60,6 +64,8 @@ Getting started
 
 #### Window
 
+| Shortcut | Description              |
+| ---      | ---                      |
 | `zz`     | Center this line         |
 | `H`      | Move to top of screen    |
 | `M`      | Move to middle of screen |