Character codes in typed text; the site and relay at app.kokkoja.com

With the Text tool, Klammertext's codes give letters a keyboard lacks:
^o" is ö, ^s^ ß, ^a1 ā, ^130ED^ a code point of 4 to 6 digits,
^9053 53EF^ a sequence, ^^ a caret, replaced as each code is completed.
The public site and relay moved to app.kokkoja.com; the old name
redirects.  The Markdown documentation is withdrawn from the release
while it is converted to Klammertext; the README's links to it are
stale until then.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -28,12 +28,12 @@ may be used.
 
 A guest needs nothing but a web browser: open the invitation link, enter
 a name, join.  A host can start a session from the same web site,
-`https://kokkoja.andykopra.com/`, with the notebooks kept in the
+`https://app.kokkoja.com/`, with the notebooks kept in the
 browser.
 
 A host who wants notebooks as files needs Python 3 and this directory:
 
-    python3 kokkoja.py --relay wss://kokkoja.andykopra.com/relay
+    python3 kokkoja.py --relay wss://app.kokkoja.com/relay
 
 opens Kokkoja in the browser; *Start a session* gives an invitation to
 send to the guests.  Notebooks are directories in `Kokkoja` in the