Fixed a number of issues before public announcement

[melissawm]

• Fixed README and index.md wording
• Moved images for consistency across binder and html site
• Added alt text where appropriate
• Removed workaround for MNIST dataset can't be downloaded automatically #63

[rossbar]

Generally LGTM - big +1 on moving the non-generated images/gifs/etc. to a static folder. However, by using the _static folder inside the site directory, the relative links (e.g. [img](../_static/...) will only work for the generated site. If a user tries to open a tutorial locally w/ jupyter notebook, the images won't be found.

I would recommend creating another _static directory in content for all of the .pngs and .gifs linked to by the tutorials themselves (site/_static contains resources only for the portions of the site that are not meant to be opened in jupyter-notebook, e.g. index.md).

I'd be happy to take a stab at that if you'd like, just LMK!

[melissawm]

I would recommend creating another _static directory in content for all of the .pngs and .gifs linked to by the tutorials themselves (site/_static contains resources only for the portions of the site that are not meant to be opened in jupyter-notebook, e.g. index.md).

That's absolutely right and something I overlooked at first, thanks!

[rossbar]

LGTM, thanks @melissawm !

The CI failure is unrelated to these changes.