feat: add command for Bitbucket Pipelines setup

[akramcodez]

Summary

Add lingo.dev init bitbucket command for Bitbucket Pipelines setup

Changes

• Added new init bitbucket subcommand under the CLI.
• Implemented runBitbucketInit() to generate or update bitbucket-pipelines.yml.
• Registered the command inside init.ts so it appears in the CLI.
• Reused the existing Bitbucket initializer logic for consistent behavior.

Testing

• Verified that running lingo.dev init bitbucket creates a new bitbucket-pipelines.yml when none exists.
• Verified that running the command again updates an existing file without duplicating steps.
• All tests pass locally.

Closes #1098

[akramcodez]

PTAL @maxprilutskiy, thanks

[maxprilutskiy]

Honest work. Thanks for your contribution @akramcodez !

[sumitsaurabh927]

@akramcodez there's a test failing, please have a look

[akramcodez]

@sumitsaurabh927 @maxprilutskiy errors solved.