Deploy to npm on a new Git tag

[notpushkin]

I’ve set up a simple GitHub Actions workflow that will release a new version on npm for every Git tag. In future, we might also want to add some tests, but for now I think this should be enough.

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@tonypconway I can’t seem to set Action secrets in the settings – at least admin access is needed. Could you perhaps bump my role? https://github.com/A-Edge/landing/settings/access

Alternatively, you can set it up yourself like this:

1. Go to https://www.npmjs.com/settings/tonypconway/tokens/granular-access-tokens/new
2. Set up a token name, some reasonable expiration date
3. Under Packages and scopes → Permissions select Read and write, then Only select packages and scopes → browserslist-config-baseline
4. Go to https://github.com/web-platform-dx/browserslist-config-baseline/settings/secrets/actions/new
5. Set Name to NPM_CONFIG_TOKEN and Secret to the token you just got

[tonypconway]

@notpushkin this LGTM as a starting point. Just so I understand - this will run any time there's a push to main?

I've elevated you to Admin privileges, so you should be able to add the token yourself 👍

[notpushkin]

this will run any time there's a push to main?

Nope, only when there are new tags – so, to release a new version, you just create a new tag (from command line via git tag v0.0.0 && git push origin --tags, or through GitHub releases).

[tonypconway]

This LGTM, merging now to assist with testing Widely Available auto-update/publish in #4