[47] ensure README.md & LICENSE is included in npm package, and add keywords

[TomStrepsil]

Issue

resolves #47

Details

The packages shown on npmjs.org show a missing README.md, and have no keywords:

To address:

• The published package should have README.md copied to the root of the package (as is the requirement for npmjs.org). However, rather than rescind the docs/ convention of the repository, a temporary copy of this file out of docs/ is made using a prepublishOnly script (and deleted after publish with a postpublish script, in-case doing a local dry-run).
• LICENSE is in the repo root, but not copied into the package, and should be based on its notice:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
  

  ...and general advice from npmjs.org

example npm publish --dry-run output:

npm notice 📦  @asos/web-toggle-point-features@0.3.5
npm notice Tarball Contents
npm notice 1.1kB LICENSE
npm notice 6.3kB README.md
npm notice 1.0kB lib/browser.es5.cjs
npm notice 6.5kB lib/browser.es5.cjs.map
npm notice 1.0kB lib/browser.js
npm notice 6.5kB lib/browser.js.map
npm notice 5.9kB lib/main.es5.cjs
npm notice 9.7kB lib/main.es5.cjs.map
npm notice 5.8kB lib/main.js
npm notice 9.7kB lib/main.js.map
npm notice 3.0kB package.json
npm notice Tarball Details
npm notice name: @asos/web-toggle-point-features
npm notice version: 0.3.5
npm notice filename: asos-web-toggle-point-features-0.3.5.tgz
npm notice package size: 9.1 kB
npm notice unpacked size: 56.6 kB
npm notice shasum: 67cfa668ce86fe4b12932c3c60d167a21920a509
npm notice integrity: sha512-nYtyHt7tE9ts4[...]Z5xSA+aO/99nw==
npm notice total files: 11

• Appropriate keywords have been added to the packages/**/package.json files.

Scout rule

• keywords had been set naively on the root package.json, and copied over when the peripheral packages were added for the open source version. However, in reality, these keywords are only used to power search on npmjs.org, so for private packages, they make little sense.
• add an .npmrc pointing to the public registry, to avoid package-lock.json pollution with private registries

CheckList

• PR starts with [ISSUE_ID].
• Has been tested (where required) before merge to main.

[TomStrepsil]

These commands pull the README.md and LICENSE files from the appropriate places into the root of the package, so that the publish finds them on the build server.

The postpublish puts them back again (to clean up local workstations, if ever running a --dry-run locally)