Document version pattern for calendar versioning

[Zlopez]

It seems that version pattern field documentation is missing in user guide. It would be good to add it, so people know how to fill this field correctly.

[chunkSpadunk]

Where in the docs is this issue the problem I can work on fixing this if the issue is still open and needs work

[Zlopez]

@skywalkersPadawan This is still open and it should be added under version scheme in this document https://github.com/fedora-infra/anitya/blob/master/docs/user-guide.rst#version-scheme

[robel16]

Hello, @Zlopez I'm an Outreachy applicant and I want to work on this task if it's still open can you assign me?

[Zlopez]

@robel16 There is already a PR open for this issue and I'm working with author to get it polished.