Add stable diffusion - stability ai - image gen

[Tim]

1. The problem

Only choice is openAI right now, can add stable diffusion as an alternative

2. Simple solution

https://platform.stability.ai/docs/getting-started

3. Screenshot examples

[Tim]

Stable diffusion now available

Added ai image selector and stable diffusion settings

Image scraper, added ai image selection dropdown

Updated default ai image prompt for images

Use img tag so macro is easier to use

OpenAI Dall-E settings added