Support non-existing tags for initial use #70
Description
Ref. the warning in the README:
If no valid latest tag is found and no fallbackTag is provided, the job will exit with an error. If using this action in a new repo without any existing tag, you should manually create the first tag (e.g. on the initial commit) that the action will compare against. Otherwise, you can use the fallbackTag option to specify a default tag value (e.g. 0.0.0).
This seems like an unecessary workaround which makes widespread use of the Action more cumbersome, since it requires "manual" steps before use.
An example of elegantly solved similar requirement can be seen in https://github.com/anothrNick/github-tag-action where you're able to define an INITIAL_VERSION:
INITIAL_VERSION (optional) - Set initial version before bump. Default 0.0.0.
In that Action, the initial version is what will be created if no existing tags exists.