Document required OpenAI API key permissions

[CHE1RON]

Check for existing issues

• Completed

Describe the feature

When asked to provide an OpenAI API key, users are told where to obtain such key, to make sure they have enough credits, etc - leaving out a key information: which permissions are required for AI assistant to work. Although I guess this would be /v1/assistants & /v1/models (as listed below "Assistants"), we could include this information while we're at it ..

If applicable, add mockups / screenshots to help present your vision of the feature