Parameterize 'dev' string in pre-release tag (OR allow free formatting?)

[needleshaped]

Dear @mdomke, thank you for the tool!

Please consider allowing more flexible formatting of the output string.

1. Use case: I usually add a branch name to version, and our developers use short dev branch name, instead of develop. Thus, end result is often confusing 1.0.0.dev.1-ce117b4b-dev (using - instead of + because Docker tags are not compatible with semver).
2. Use case: When explaining to developers as DevOps engineer new proposed versioning scheme based on your project, I often need to mention, that .dev = number of commits since the last commit, which is not self-evident. I would either completeley remove it, or replace with .commit, which would make it self-evident.

I'd like to avoid post-string-replacement (s/.dev/.commit/), thus asking you here.

Essentially it means a new variable for this line

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P.S. This may be solved, with making format itself configurable. As of now, you have hardcoded choice of formats.

• Existing tool that implements it this way, is e.g. date, date +%Y%m%d-%H:%M:%S,
• This would result in usage: git-semver -format '%X.%Y.%Z-dev.%N+%S'. (%S - SHA)

Such method would also allow other functionality to be easily added, e.g.

• like branch name %B, while preserving default format intact
• or making generated version compatible with Docker tags out of the box.
• will allow to use user-defined $VARIABLES in a format string, which opens complete freedom, without a need of post-processing.