Add a condensed-navigation-tab option

Description

For people that use screen in portrait mode or split screens that tab-navigation-bar is often too small to include all useful links, especially when bugs are separated from issues.

We should have an option to enable a more condensed more where one of the following measures could be used:

• less spacing between buttons
• Remove text for most common options as we already have icons
• Replace text with shorter version, like Pull Requests could easily be PRs.

Screenshot

No response

Example URL

https://github.com/sindresorhus/refined-github

[yakov116]

Do you mean the below?

While I’m at it, here’s a related “refinement” that won’t be part of Refined GiHub 😃

.UnderlineNav-octicon {
	margin-right: 0 !important;
}
.UnderlineNav-item [data-content] {
	display: none;
}

_Originally posted by @fregante in https://github.com/sindresorhus/refined-github/issues/4286#issuecomment-831005339_

[fregante]

Maybe we can enable these styles on small screens

I like that. I’d rather hide the labels than hide everything in the dropdown, especially on a phone screen.