feat(adapter): Load adapter from local disk

[joeyguerra]

• load a .mjs file as an adapter (ES6 import
• load a .coffe, .js or .cjs file from local disk as an adapter (e.g. -f ./adapters/CustomAdapter.coffee, -f ./adapters/CustomAdapter.js, -f ./adapters/CustomAdapter.cjs)
• introduce new cli argument -f (file) that specifies the adapter path and file to load the adapter, e.g. -f ./adapters/CustomAdapter.mjs

BREAKING CHANGE: ES6 import is async, thus loadAdapter was changed to an async function.

1624

[joh6nn]

I can't say that it's good, only that it isn't obviously egregiously bad :shrug: If nobody else is able to step in for a real review in the next day or so, message me and we can do a quick walkthrough of it on like Slack or Discord or whatever works

[joeyguerra]

Sounds good. Thank you.

[joeyguerra]

@xurizaemon @technicalpickles I've incorporated ya'lls suggestions.

• Separated the concepts of loading an adapter from an artifact registry (i.e. npmjs via hubot-slack) from a file via -f ./adapters/CustomAdapter.{js|mjs|cs|coffee}.
• Replace double negative phrasing
• Updated commit message that removes loading scripts from external-scripts.json

[github-actions[bot]]

:tada: This PR is included in version 5.0.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: