Code formatting and automation

[Pete-Robelou]

• [x] Update Prettier to latest version and run format script to make consistent.
• [x] Implement husky and lint-staged to ensure files edited are formatted as they make their way into the repo on precommit.

Some references:

• https://codeburst.io/continuous-integration-lint-staged-husky-pre-commit-hook-test-setup-47f8172924fc
• https://www.joshuacolvin.net/git-hooks-with-husky-and-lint-staged/

[adamduncan]

@Pete-Robelou On second thoughts here, perhaps we forgo running a sitewideformat across the codebase. Content contributions are starting to come in, so wouldn't want to create unnecessary conflicts.

Would still suggest we update Prettier and set up husky / lint-staged, that way files will progressively fall into the pit of formatting success as they're subsequently re-commited over time.

Would be good to run Prettier locally all the same, to gauage how many files would be affected by a blanket reformat.

[Pete-Robelou]

Installed latest versions of husky and lint-staged and also updated prettier to the latest.

Configured lint-staged and prettier to look at the same files js|json|css|md|html.