Relates to #123.
While this does not introduce "per-branch" tag parsing it does allow an
alternative tag sorting method which maybe a better solution.
With this commit the user can decide to sort the tags by semver instead
of dates.
This is useful where repositories are utilizing a stable branch model
and back-ports are interleaved with new releases.
For example, if your mainline is on v3.0.0 with it's last release
1/1/2021 and a back-port release of v2.0.1 is released on 1/2/2021,
sorting by semver will correctly order the change log producing
v2.0.1 -> v2.0.1 -> v3.0.0
This functionality is completely opt-in and defaults to the original
"date" sorting
Signed-off-by: ldelossa <louis.delos@gmail.com>