infra: CI manages release process

[thompson-tomo]

This introduces github workflow for managing releases. This workflow is triggered when a tag is added to a commit and performs the following:

• Set npm package version based on tag value
• Create npm package
• Uploads npm package to npm
• Create github release with npm package attached and auto generated release notes

Required steps by maintainers:

• Setup trusted publishers https://docs.npmjs.com/trusted-publishers/
• Go to github tags and starting from 0.6.0 (or earlier) create a release for each tag by clicking the create release option, followed by the create release notes option to generate release notes.

[thompson-tomo]

This has implemented the review feedback in thlorenz/doctoc#289

[thompson-tomo]

@AndrewSouthpaw / @thlorenz how can we progress this release process automation pr as this library is now ready for a release?

[AndrewSouthpaw]

Unfortunately, I don't have admin access to anchor-markdown-header in npm, only to doctoc.

@thlorenz could you add me as a collaborator so I can set this up?

[thompson-tomo]

Thanks @AndrewSouthpaw note that the CI pipeline has been defined such that even if the npm upload failed the creation of the github release would still complete. This github release would contain the files which could be uploaded to npm.