Standardize repo name to `erb_lint`

[george-ma]

Context

Someone pointed out that the erb_lint gem has inconsistent naming.

• The repo is named erb-lint https://github.com/Shopify/erb-lint
• The gem in RubyGems is named erb_lint
• The config file that gets created is .erb-lint.yml
• The executable for the gem is erblint

RubyGems will block anything less than 4 edits away to an existing gem over 10M downloads.

So even though this gem cannot be typosquatted due to RubyGems restrictions (eg. publishing a gem named erb-lint instead of erb_lint), it'd be good to make changes to unify on a naming in the repo.

What is this PR?

This PR aims to resolve the inconsistencies seen above and patches references to erb-lint in favor of erb_lint. We're choosing erb_lint as its the gem name (.gemspec) which is the hardest to change

Proposed Changes

• [X] Point all links to go to Shopify/erb_lint instead (even though GH does an auto redirect).
• [X] Add support for the library to read from either .erb_lint.yml or .erb-lint.yml and warn that the latter will be going away soon and urge folks to rename their yaml file today. https://github.com/Shopify/erb-lint/blob/f82b3f7473dd1a0a966638c7f28b6ea213198b6a/lib/erb_lint/cli.rb#L16
• [X] Add a new binstub named erb_lint and when erblint is called, we could similarly warn about its usage and just call the erb_lint one under the hood. https://github.com/Shopify/erb-lint/blob/main/exe/erblint

Note: I did not change the name defined in dev.yml to erb_lint because of:

Next steps:

• [X] Rename the actual repo to erb_lint.
• [ ] Point all links to go to Shopify/erb_lint
• [ ] Update all related tooling since we're renaming the binstub https://github.com/manuelpuyol/vscode-erb-linter

[runephilosof-abtion]

Please release a new version with this change, since the main README now tells you to run erb_lint while that has not been released.

[mvz]

Someone pointed out that the erb_lint gem has inconsistent naming.

That would be me in #322. Thanks for taking care of this!