* KnownIssues: reformat, reorganize, clean up
- fix bad tabulation in rendered markdown. GFM is very forgiving with tabs, but most implementations require four spaces per level.
- fix headers and header depth (H3 should not be the toplevel...)
- convert some list items to headers
- fix some grammar and reword some parts
- reorganize some list elements and sections
- unify use of key shortcut presentation (`Win`+`X`)
- convert some quoted words to italics
- don't include punctuation in emphasized/quoted technical words
- better explain some of the troubleshooting steps
- add key takeaways to battery health section
- other general proofreading
* KnownIssues.md: add clarifying text
