dead link for ConnectorSpecification in docs for cdk python tutorial

[leo-schick]

Tell us about the documentation you'd like us to add or update.

There the first link ConnectorSpecification in the first paragraph is dead.

If applicable, add links to the relevant docs that should be updated

• Link to relevant docs page

[juweins]

Hey, thanks for the hint! I will quickly fix this 👍🏼

[juweins]

@sajarin @leo-schick : I assume it is supposed to forward to this page: https://github.com/airbytehq/airbyte/blob/master/docs/understanding-airbyte/airbyte-protocol.md#spec

[juweins]

@marcosmarxm This issue closes with PR #21081

[sajarin]

Thanks @juweins for the fix!