Documentation for `label()` template function does not mention its usage

[Vampire]

From just reading the documentation for label() at https://jj-vcs.github.io/jj/latest/templates/#global-functions which only says

Apply label to the content. The label is evaluated as a space-separated string.

It was totally unclear for me what it is used for and trying it out did not show any visual difference.

Only be reading the whole page (or in my case asking someone) you find out that it is used to colorize something.

It would be nice if the docs for the function would mention what it is used for and / or link to the "Color labels" section https://jj-vcs.github.io/jj/latest/templates/#color-labels where it is further explained.

[ilyagr]

I tried to improve the situation in #7780, feel free to take a look and tell me what you think.

[Vampire]

Much clearer imho, thanks. :-)