docs(ts/index): warn of beta-11 zone errors

Author: wardbell

public/docs/ts/latest/index.jade

@@ -1,3 +1,14 @@
+.alert.is-critical
+  :marked
+    The current beta.11 release has known bugs relating to
+    significant changes to the  _zones_ subsystem.
+    All apps will report an error to the console:<br>
+    <span style="color:red; font-family:Lucida Console;">
+    Uncaught TypeError: Cannot read property 'zone' of undefined</span><br>
+    The app will run unimpeded but it is disconcerting.
+    We hope to have this and other bugs repaired by beta.12.
+    Thanks for your patience.
+    
 div.card-row(layout='row')
   div(flex)
     md-card.card