Fix table formatting in README

README.md

@@ -210,6 +210,7 @@ level. This will override the default battery icon. In order to do this, you
 need to define the `POWERLEVEL9k_BATTERY_STAGES` variable.
 
 | Variable | Default Value | Description |
+|----------|---------------|-------------|
 | `POWERLEVEL9K_BATTERY_STAGES`|Unset|A string or array, which each index indicates a charge level.|
 
 Powerlevel9k will use each index of the string or array as a stage to indicate battery