Github actions workflow to automate tasks when a Caliper release is tagged

[davidkel]

Things like

• publish a version of the docs for that tag
• publish official docker images and npm modules
• bump the code to the next unstable version

Basically anything listed in the Release_process.md file which could be automated

Note Mike (used by the docs) cannot do anything with github to automatically update the docs (even if we change the branch to not require PRs have a ruleset the locks down the branch) as it uses the git command and the actions token is only authorised for Rest api calls.

There is a solution to this via the official github actions that can update gh-pages in conjunction with mike creating the content locally. Would require checking out gh-pages and generating the content via mike on that gh-pages version.