fix: combine content of givingthanks example to one line per ERRATA

Author: evanp

notes-on-extensions.md

@@ -0,0 +1,5 @@
+- Extensions in the specification
+- Extensions on the namespace page https://www.w3.org/ns/activitystreams#extensions "This namespace may be used by extensions to AS2 which are considered stable. The extensions must document their terms in a spec-like way at a persistant URL. Approval of extensions will be by the Social Web WG until it closes, and after that by the followup Community Group. Process and criteria for extensions approval is being finalised and will be described or linked to here in due course."
+- Extensions on the wiki https://www.w3.org/wiki/Activity_Streams/Primer/Extensions
+- Propose publishing a note on how extensions are included in the main context
+

vocabulary/index.html

@@ -6516,9 +6516,7 @@ <h2>Mentions, Tags and Other Common Social Microsyntaxes</h2>
   "@context": "https://www.w3.org/ns/activitystreams",
   "name": "A thank-you note",
   "type": "Note",
-  "content": "Thank you &lt;a href='http://sally.example.org'&gt;@sally&lt;/a&gt;
-      for all your hard work!
-      &lt;a href='http://example.org/tags/givingthanks'&gt;#givingthanks&lt;/a&gt;",
+  "content": "Thank you &lt;a href='http://sally.example.org'&gt;@sally&lt;/agt for all your hard work! &lt;a href='http://example.org/tags/givingthanks'&gt;#givingthanks&lt;/a&gt;",
   "to": {
     "name": "Sally",
     "type": "Person",