Put all prompts under MIT license

[JonasHelming]

fixed #15158

What it does

In our repository (Theia), we have several prompt templates.
These templates are strings and are user editable, so the user has a UI to change them at runtime in the tool. As we do not want to get into any license discussions and allow users to adapt their prompts, this PR extracts all prompt templates to separate files and changes their license to MIT for these prompt templates.

The PR also adds a plain MIT license file to the repo, as the existing one is targeted at VS Code code.

See here for more details, we will let contributors agree on this PR on the re licensing

How to test

All agents should work without any change.

Follow-ups

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[JonasHelming]

@msujew No technical review is needed from you, but could you check and +1 the general operation as a second project lead before I ask all contributor to +1 on the PR, please?