[docs] Fix Colab notebook cells

[stevhliu]

Fixes some Colab cells where the code example doesn't run out of the box because it was a bash snippet. Now users just have to uncomment the cell to run it. I've also added notebooks for several other pages that were missing it, and removed the [[open-in-colab]] cell from the Training guides because those are mostly focused on using the training script.

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[yiyixuxu]

thanks!

still don't know why this doesn't work for us though, https://github.com/huggingface/diffusers/blob/main/docs/source/_config.py

[sayakpaul]

Thanks so much! Definitely helps the users more.

I also agree with @yiyixuxu's comments here. @mishig25 any hints?

[patrickvonplaten]

Very cool!