Add docuentation on how to install styles

[gunchleoc]

Describe the change you'd like:

It would be good to have some user documentation in the FAQ on how to use these styles for non-techy people, e.g. by providing a list of linked add-ons.

For Firefox, I found this one: https://addons.mozilla.org/en-GB/firefox/addon/styl-us/

[Freeplayg]

Isn't there already this?

Although, maybe it would be better for the button to bring you to a page to let you choose which browser you're on to install it (and then maybe use JS to auto-detect the corresponding one), rather than just bringing you to a readme of the extension

[gunchleoc]

As somebody who has never done this, I had no idea what the button is for, so I ignored it.

[Freeplayg]

Maybe there could be some sort of banner at the top of the page if you don't have the extension installed to say to install Stylus to install styles?

[vednoc]

Since you didn't click on "Get Stylus" button, I suppose we could hide "Install" button when Stylus isn't available and rename "Get Stylus" to something more descriptive, which would redirect you to a setup page in our documentation.

[Freeplayg]

Maybe not hide the button, since there are other extensions for styles aren't there?

[vednoc]

There are two other ones that I'm aware of. We could add an option to USw Tweaks that always enables "Install" button, similar to what we do with "Get Stylus" button.

[gunchleoc]

I like the header idea. There could be a link in the header next to the "Explore" link. Call it "Install" and have it show a page with listed compatible extensions?