Update Node.js requirements, ESLint, ruleset names; drop Make

[danyalaytekin]

Note

This PR drops the makefiles and make verify in favour of npm test. While pottering here I had noticed the Makefile.node's generator, rowanmanning/makefiles/Makefile.node, had been archived in 2017, and its successor project in 2022, so at first I thought I was just going to (1) remove the connection between them and that would be that.

Later I realised the flexibility of the remainder of the makefile and didn't think it made sense to keep this flexibility with the connection severed which led to (2) pruning the tasks to match the requirements of this repo's build. With this completed the flexibility of Make itself no longer seemed necessary either leading finally to (3) the replacement of make verify with npm test.

I hope this is all sensible @rowanmanning but please let me know if I've misunderstood something or you had another plan in mind for this repo.

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This PR makes the following changes:

1. updates Node.js support to 18 and 20 (current LTS versions) from 12+
2. upgrades ESLint to ^8.51 from ^7.27
3. upgrades native Actions checkout (to 4) and setup-node (to 3)
4. replaces make verify with npm test
5. sets workflow to trigger on push to either master or main, and for PRs targetting any branch, renames job to test, and deletes comments and names where the file's content is already descriptive
6. adds migration guide for anticipated v3
7. sets es2017 as default
8. drops es2015's alias es6, legacy's alias es5, and renames legacy to es2009
9. adds lockfile to source control
10. in the readme fixes a typo in the printf > script and some references to older naming of this package

It's accompanied by changes to repo settings:

• Default branch renamed to main from master, part of Rename the 8 default branches to main from master org#19
• Replace TravisCI PR guard with GitHub Actions guards for 18 and 20
• Automatically delete head branches
• Limit how many branches and tags can be updated in a single push (to 3)
• Stop displaying the empty Packages section on the right, because they're in npm not GitHub's registry

[josebolos]

chefs-kiss.bmp