Look for Whitespace Errors

[arnavs]

Let's say @WenxinM does the first three sections, and @aadsouza does the last two (the first section, "Introduction", is just one lecture.)

Per @mmcky:

Sometimes a > will crop up in myst files that have been generated by sphinx-tomyst. That is because a lot of users get white space wrong in rst so any form of incorrect indentation wraps items in a block_quote object within the sphinx.ast. So these are something to keep an eye out for.

Let's find and fix these if possible. This should be doable based on the source itself. Basically find occurrences of that character and see if they correspond to a valid block quote on the website.

[aadsouza]

Pushed whitespace error fix for reshape.md