RFC: Add banner warning when on version other than "release"

[qpwo]

Here's a screenshot of what python's looks like:

[bigtimebuddy]

Great suggestion. This is a feature that would need to be added to this template.

[qpwo]

In tmpl/layout.tmpl or where?

[bigtimebuddy]

Yeah, probably. Since this docs template is used for a variety of projects, this feature should be opt-in. I imagine that the user defines the location of the latest docs and if the URL doesn't match, it shows the banner.

[qpwo]

You opt in by providing that URL, and if that has not been provided, then you show no banner? And where exactly would that option be set in https://github.com/pixijs/pixijs ?

[bigtimebuddy]

Probably somewhere here: https://github.com/pixijs/pixijs/blob/dev/webdoc.conf.json