Feature: Tutorial approval process

The docs at https://makecode.com/writing-docs/user-tutorials describe a tutorial approval process that is not fully documented. This ticket is to setup a lightweight process so that the Foundation and MakeCode can have some QA over submissions without discouraging or preventing anyone creating a tutorial.

Currently, people can create Tutorials on their own or add them as part of documenting an extension. The process is the same as extensions, you have to create a release to include a tutorial

Suggested workflow

1. Submit it to Foundation as part of an extension. We won’t expect or need to approve all individual tutorials eg those by a teacher.
2. PR raised and Foundation and MakeCode team review as with Extensions.
3. Tutorial is added it to a third party tutorial gallery page

Assumptions
- License: MIT as with extension, no additional licenses required
- Unapproved content removed from the title bar when the tutorial is approved.
- Identification get email address/github/twitter ID/phone number/linked in? public profile.
- Must join a tutorial-authors Slack Channel
- If repo gets reported to MS Github, Foundation also need a notification

TODO

• Create third party tutorial page
• Update docs https://makecode.com/writing-docs/user-tutorials
• Update KB https://support.microbit.org/support/solutions/articles/19000054952-makecode-extension-approval

Start with the user-tutorials documentation linked in the issue and compare it with the existing MakeCode extension approval KB article. Update the documentation to describe the suggested tutorial approval workflow and the listed assumptions, with the approval process and third-party tutorial gallery relationship clearly covered.