Improve accessibility with descriptive texts for <svg> and other diagrams

[duerst]

The current RFCs with diagrams are very thin on descriptive texts with the <title> and elements. This makes it difficult or impossible for sight impaired readers to understand these diagrams, and therefore the RFC they contain. Part of the improvement needed are documentation issues (see e.g. ietf/authors.ietf.org#42) or tools issues (see e.g. ietf-tools/svgcheck#21).
What this issue is about is the policy issue of requiring the RPC to check <title> and elements in diagrams and other alt-text to make sure that the needs of sight impaired readers are covered.
If the RPC tells us they don't need policy in order to add this to their list of work when publishing an RFC, then all the better (and this issue can be closed).

[ajeanmahoney]

The RPC is updating its procedure for checking artwork to include reviewing the contents of the SVG <desc> and <title> elements and the <artwork alt=""/> attribute (when xml2rfc supports it. Issue opened: ietf-tools/xml2rfc#898). If the artwork lacks an accessible description, during AUTH48 the editor will ask the authors to please provide text. We will also update the Online Portion of the Style Guide to recommend to authors that they provide descriptive text for artwork. rfc7322bis already captures a recommendation regarding artwork accessibility.