Add code conventions via linting/prettier tooling

[0xjjpa]

Is your feature related to a problem?

Currently there are no code conventions on the project.

Describe the feature you'd like

Ideally we use something like js-standard and enforce via prettier and githooks to run linters on commit/push.

Describe alternatives you've considered

Auto-commits as we do in hoprnet, but CI feels like the wrong place to deal with this (wasting CI cycles on code that wasn't verified in the workstation).

Additional context

This is relevant for our contribution guidelines.

[mjadach-iv]

Closing issue as the myne-chat project is closed for the time being.
Will need to reopen if we will be updating the repo.