You can now switch insights to "query" mode but the UI flow to edit them is different to other insights
Was a stacked branch... work really begins at commit e3b979c
# Problem
You can add gifs and images to text cards but need to know how to write markdown (and realise it is possible)
# Changes
* Adds an API (authenticated) to allow image upload
* Adds an endpoint to view images (immutable cache headers set)
* Adds some basic validation
* Adds UI to allow drop of file onto a text card (well, any component using the LemonTextMarkdown) to upload the image and insert a link to it in the markdown content
