[DOCS] References to keystore module, keystore does not exist

[nf-brentsaner]

Description
https://docs.saltproject.io/en/latest/ref/states/all/salt.states.keystore.html

However, this module was removed in dc526dc

Guys, if you're going to remove modules, at the LEAST update the documentation.

Suggested Fix
Better project leadership and/or processes.

Type of documentation
Documenting non-existing features.

Location or format of documentation
See above

Additional context
This was improperly handled. I wasn't even aware of the purge until I looked for, and found documentation for, a module that does not even exist anymore, wasting some time confirming the module does not actually exist, and wasting FURTHER time researching why it was missing which I found via a third-party non-SaltStack-affiliated resource online. No mention of removal of this module was in CHANGELOG.md.

This is not how business-critical projects are run.

[nf-brentsaner]

This page, of course, does not exist at https://docs.saltproject.io/en/master/ref/states/all/salt.states.keystore.html.

But you know what isn't present on the current page?

A deprecation notice. Something that Salt normally does for deprecations in documentation.