Additional references for italic and bold

[jsnmrs]

References to add to https://doublegreat.dev/listen/bold-and-italics/:

• em and strong are not announced by screen readers
• Screen Read­ers Don’t Con­vey the Seman­tics of STRONG and EM
• Screen Readers support for text level HTML semantics
• Screen Readers lack emphasis

References to add to https://doublegreat.dev/listen/punctuation-in-alt-text/

• How screen readers read special characters: an update