wip: eslint support

[43081j]

its been a while since i did this so i still need to catch it up from master and double check where i got to.

basically, though, its current state is:

• remove TSLint
• recreate tslint config equivalent in eslintrc.json
• lint this repo itself using ESLint
• fix any outstanding lint errors in this repo after moving to ESLint
• update the CLI to use eslint and output/fix up eslint configs rather than tslint (done but not tested)
• update individual rules to use ESLint

i have already tried to move the npm naming rule by the looks of it, though given the build doesn't pass yet i can't see if i did that right or wrong.

cc @orta