[Feature Request] init image support

[Ratinod]

I really want to be able to use a specific image as a starting point. There is an example and places how this can be implemented for the original (AnimateDiff) repository. https://github.com/search?q=repo%3Atalesofai%2FAnimateDiff%20init_image&type=code

Maybe you can adapt code for this repository?

And a little extra question: How to update animatediff-cli correctly? "git pull" and then "python -m pip install -e . " ?

[Ratinod]

Starting and ending frames concept: https://www.reddit.com/r/StableDiffusion/comments/15xq294/controlling_animateddiff_using_starting_and/