conformance challenges 5aside (#2149)

* New branch to try <aside> for Silver Research; also (temporary) italic styling for mitigations.

* added mitigation class in Introduction for the two paragraphs that discuss mitigations.

* Removed an errant <section> tag.

* Restyled with divs; Mitigations as italics; Silver Findings as bold; Used two <aside> statements saying note the styling.

* Fixed coding in a code block just above Appendix A.

* Initial move of 'Silver Findings' to Introduction/Background. Text trimming to follow.

* Putting the Silver Research div back higher in the Intro section, just above the Mitigations <h3>.

* Prototype draft with Silver Research as Appendix C and proto-styling for Silver Research Findings integrated in the doc; also for Mitigations.

* Additional intro text for Silver contribution to Challenge #1; a couple coding fixes.

* Slight rewrite to Silver addition to Challenge #4.

* Attempting to correct appendix lettering; Acknowledgements is now App D.

* Undo of titling in App. D

* Numerous textual updates and edits through the Introductory sections.

* More textual updates and edits up to, but not including appendices.

* Additional text edits

* Catching grammar as I can -- this time 'may' vs 'might.'

* move class to section

* Exchanging 'important' for 'valid' in our Problem Statement to avoid even a hint of value judgement.

* Accepting @bruce-usab's #1629 citation but not removal of the 80% bullet list item.

* Added language to Challenge #5.

* Added text to Challenge #6.

* Added Challenge #5 para for WCAG-EM approach.

* Changed 'poorly' to 'insufficiently' in Challenge #5 to soften the bite.

* Some typos and missing class attributes on Challenges 5 & 6.

* Adding hyperlinks throughout for WCAG 3.

* Removed 'Versioning' challenge #6 for now; Re-arranged #5 to more clearly indicate what we add vs what Silver provides via Appendix C.

* Added conformance implications paragraph to Challenge #5; ran tidy.

* Further textual tweaks to Challenge #5.

* Reworked first two paragraphs of Challenge #5.

* First fixes under Challenge #5; added Silver Findings under Challenge #3 with hyperlink to Appendix C.

* Quote fix for Silver Findings under Challenge #5.

* Adding Peter's edits to the opening paragraph(s) of Challenge #5.

* Rewrote the two bullet points for Silver Findings under Challenge #1 to use direct quotations; Provided cross links into Appendix C.

* Fixed a couple hyperlinks.

* Various fixes for missing element closure; also changed apostrophes to &apos; throughout.

* New initial paragraph introducing Appendix C.

* Fixing typos -- my tendency to type the carat where I intend the ampersand.

* Two grammatical corrections

* Testing referent respec markup; adding 'Content Usable' shortname

* Fixing section nesting; also using respec's ID href ml.

* Typo--missing space

* Still working on section nesting--this probably won't finish the job.

* Still working on correct section nesting ...

* Rewrite of Challenge #5, especially references to WCAG-EM and the Mitigations section.

* Working on some anomolies in the Introduction ...

* Removing the two one paragraph sections ending the Introduction; Adding the class attribute to the <p> tag

* Shortened the Intro subsection that introduces our mitigations.

* Incorporating PK's edits to Challenge #5.

* Fixing a missing mdash.

* Withdrawing promisses of future content in this document.

* Removing more promisses.

* Moving reference of WCAG 2.1 Conformance to point specifically to the quoted Sec. 5.2.4.

* Revert "Moving reference of WCAG 2.1 Conformance to point specifically to the quoted Sec. 5.2.4."
While we're first quoting 5.2.4, our next URI is the specific pointer to
5.2.4. So, it seems best to leave things as they were.

This reverts commit 9a8e1c6.

* Fixed a URI reference in Challenge #5 re the need for 'international discussion;' reworked the internal reference to Challenge #1.

* Because bold is a CSS fond-wight, not a font-style

* Yet more promise at head of Appendix A

* Fixes typo in quotation markup in Challenge #5.

* Wording change in Challenge #5; changed 'approaches to' to 'approaching.'

* Wrapping UX into an abbr tag on it's use inside our enumerated Challenges. Not wrapped in Appendix C.

* Adding class='notoc' to Appendix A <h3> and Appendix <h4> tags

* Some minor typos, etc

* Streamlining to class='appendix notoc' hoping to influence respec!

* Last syntax change works, but I missed exactly three!

* Trialing quotations in CSS darkred; plus one spelling fix.

* Adding PK's wirte-up of Challenge #5 to Abstract.

* Removed the backslash in Abstract, Challenge #5. It's being taken literally, not as an escape char indicator.

* Reverting respec-specific Appendix URI markup; also fixing resulting apparent sentence fragment in Silver Findings of Introduction.

* One more respec Appendix reversion; fixed duplicated 'for' in Challenge #5.

* Fixed four malformed hyperlinks from the respec reverts. Now validate.

* Adding PK's edits to the Silver Findings section of the Introduction. We'll likely do more edits there, though.

* Updating reference to Content Usable as it's now a W3C Note.

* Updating contributor status for Janina Sajka

* Updating status for Janina Sajka, Editor

* Fixing Editor and Author citations for Janina Sajka

Co-authored-by: sajkaj <sajkaj@amazon.com>
Co-authored-by: Michael Cooper <cooper@w3.org>