Some modern terminals allow creating tabs in a single window;
this functionality has a lot of overlap with what a window manager
already provides, so I'm not sure if it's a good idea. Regardless,
a lot of people still use terminal tabs (or even multiple levels of
tabs via tmux!), so let's add a fish-native way to set the tab title
independent of the window title.
Closes#2692
No need to define "cmd-foo" anchors; use :doc:`foo <cmds/foo>`
instead. If we want "cmd-foo" but it should be tested.
See also 38b24c2325 (docs: Use :doc: role when linking to commands,
2022-09-23).
This makes it so we link to the very top of the document instead of a
special anchor we manually include.
So clicking e.g. :doc:`string <cmds/string>` will link you to
cmds/string.html instead of cmds/string.html#cmd-string.
I would love to have a way to say "this document from the root of the
document path", but that doesn't appear to work, I tried
`/cmds/string`.
So we'll just have to use cmds/string in normal documents and plain
`string` from other commands.
Unfortunately, currently :program: doesn't link to the program's page.
So we use the old-school :ref: again where we should link, i.e. for
everything that's not the program the current page is about.
Fixes#8438
