Add version specific urls to release template

[LeeLenaleee]

Did not know of an easy way of testing this, but according to the docs this should work 🤞🏻

https://github.com/release-drafter/release-drafter#example

#11035 (comment)

[etimberg]

lets give it a try

[LeeLenaleee]

It works, draft release now points to https://www.chartjs.org/docs/4.3.0/migration/v4-migration.html which does return a 404 now because 4.3.0 did not release yet