feat: add "--ignore" flag to deno fmt

[littledivy]

Adds --ignore to deno fmt

Use case:
deno fmt --ignore=./node_modules/

Status:
Ready for review

Ref: #4459

[nayeemrmn]

I wonder if we should go with --exclude. The ignore name is used for something slightly different for deno test -- it might be confusing when we bring this over there.

[littledivy]

I think "ignore" is more standard and easy to guess but i think you're right as it is used in deno test for a different purpose.

[CLAassistant]

All committers have signed the CLA.

[littledivy]

Changed --ignore to --exclude and added --unstable check.

[nayeemrmn]

@divy-work Sorry, I think we should go back to --ignore to match // deno-fmt-ignore. For deno test we can use --ignore-files, having both --ignore and --exclude would be confusing anyway.

[littledivy]

@nayeemrmn No worries. Switched back to --ignore.

[ry]

LGTM - thanks @divy-work ! (Let's remove the --unstable flag before the next major release on August 13)