Composition settings: Verbiage adjustments

Currently:

Proposed:

> Markdown
Write your posts or pages in plain-text Markdown syntax. Markdown is an easy writing system favored by writers that allows you to quickly write and edit the format of elements such as headers, lists, and more.

> Editing Tools
Proofread your posts and pages automatically with our intelligent editing tools. Write more content, faster. We'll handle tidying things up for you.

@benhuberman I'm getting into the groove of explaining the benefits of these features to customers, but I'd like a little direction here. We have sub-settings for the proofreading section. To me, they seem alright and self-explanatory. Do you have any recommendations for these?