Feature / extention request to add custom info/notes to pnginfo

[onusai]

I think it would be helpful if we could add additional info / notes to the pnginfo. This would enable users to add an "authors note" or links to their models/embeddings so others can find them easily

There's a couple ways this could be implemented:

1. an option in the settings tab where you can write a custom note which gets added to all images. this could be useful to add your discord/twitter/etc username or links to your repos

2. an option in the txt2img tab where u can write a custom note which gets added to the current images your generating. this could either replace, append, or mirror the option in the settings tab. this would be useful for when you want to add notes that are only relevant to the immediate images your generating and will be changed often

3. a little out of scope, but it would also be nice if we could edit an images pnginfo in the pnginfo tab

i think this would be nice as a native feature, but if someone can implement this as an extension that would also be amazing