Categories on the left should have the descriptive tooltips used elsewhere

[roryokane]

On a plugin page such as https://vimawesome.com/plugin/fugitive-vim, the plugin’s category is shown at the right. When hovering that category, and when hovering over other categories in the editing menu, descriptions of each category are displayed in tooltips:

However, the global left sidebar has no tooltips:

Those descriptive tooltips should be added to the left sidebar so you can remind yourself what a category means without having to go to the top of a plugin page.

Care should be taken that the tooltip doesn't cover anything important. One way to accomplish that would be to delay the appearance of the tooltip, as with OS-native tooltips.