Update whats-new.md

src/_about/whats-new.md

@@ -18,6 +18,14 @@ title: What’s new?
 * va-file-input: add support for read-only mode by @pennja in #1300
 * va-date: add prop to make month optional by @it-harrison in #1377
 
+### New content guidance
+* Claims and applications (under Specific topics and programs): New page with general guidance for content about claims and applications #3504 
+* Email and text notifications: New page with general guidance for email notifications #3406
+* Bulleted lists: Clarification on single sentences in lists; crosslink with radio buttons and checkboxes #3268
+* Use short sentences (under Plain language): New example and suggested guideline for maximum sentence length #3268 
+* Sign in and identity verification (under Specific topics and programs): Updates to word list related to sign-in changes and clarification on when and when not to use "verify your identity"
+* Word list: New entries for claimant, sponsor, Philippines, and Washington, DC #3513
+
 ### Bug fixes
 * va-modal: set box-sizing to border-box to prevent text overflow by @powellkerry in #1357
 * va-accordion: open accordion when media is print by @ataker in #1363