Reorganize install and getting started docs

[Archmonger]

Description

It seems that some users are having trouble differentiating between Getting Started and the Installation section. So I've gone ahead and merged them.

Changelog

• Reorganize install/getting started docs
• Misc. verbiage changes for clarity
• Fix docs edit button
• Add readme badge for docs
• Clean up readme label for PyPI badge

Checklist:

Please update this checklist as you complete each item:

• [X] Tests have been included for all bug fixes or added functionality.
• [X] The changelog.rst has been updated with any significant changes, if necessary.
• [X] GitHub Issues which may be closed by this PR have been linked.