Allow running as bitbucket pipe

[taraspos]

Hey!

I added all the needed changes to be able to run this as bitbucket pipe. However, bitbucket allows running pipes only from public images.

Would it be possible to publish this to Docker Hub as reviewdog/action-languagetool:1.5.0 #19?

I had to add setting the default values in the entrypoint.sh script itself. Even if pipe.yml supports the default key, it doesn't set the value automatically and needs to be set in the code :/

This PR depends on reviewdog/reviewdog#815

[shogo82148]

it sounds good.
But, I think The BitBucket pipe should be in a separated repository from the GitHub Action.
We currently use a Docket GitHub Action now, but we might migrate into a Composite Run GitHub Action (e.g. reviewdog/action-golangci-lint#46) or other action types in the future.
Targeting only GitHub Actions makes it easier to migrate.

@haya14busa How do you think?

[taraspos]

Separate repo is fine for me, I just wanted to reuse all the scripting without the need to copy&paste it.