Formatting updates to guidelines

[jehlers]

Using this pull request to work on the formatting of the guidelines page. Specifically:

• [x] Taking out the checkboxes
• [ ] Adding / figuring out how to add the TOC
• [ ] Fixing the formatting of block quotes
• [x] Fixing the formatting of H5s
• [ ] Making some of the images smaller

[jehlers]

@tadhg-ohiggins Looking back at this. If we want to post the blog post next week, we can. The images aren't perfect (some are a little too big at eregs.github.io/guidelines) but the rest of the above checkmarks are my design OCD kicking in. I leave it to you. If you agree that w/o the TOC TBD placeholder, this is good to at least publish then 👍! If not it can wait until I'm back, but the comment period will be closed then.

If we publish as is now, I can still fix the images and other things when I'm back. But this is the MVP. ;)

Only thing still needed is, IF we publish this, we need to add it to the sidebar. I think that happens in the config file. See @cmc333333's PR about governance policy.

[cmc333333]

No harm publishing a page and linking to it later