'smv_released_pattern' examples should start with 'refs/'

[LewisGaul]

The example regex patterns for smv_released_pattern start with ^tags/, ^heads/ and ^remotes/, however this appears to be missing the required refs/ at the start. I was seeing everything failing to match until I made it ^refs/tags/.*$.

See https://holzhaus.github.io/sphinx-multiversion/master/configuration.html.

Thanks for the tool :)

[tonywhittam]

Thanks @LewisGaul. I was having this issue and confirm that it works exactly the way you said.

[BurningEnlightenment]

Duplicate of #59