Add 3.4 what's new

Author: okorach

doc/what-is-new.md

@@ -1,11 +1,14 @@
 # Next version yet unreleased
 
+# Version 3.4
+
 - `sonar-tools` is now available as a docker image
 - `sonar-config`
   - Export can now export configuration as a YAML file (Only JSON was available previously).
     Import of YAML is not yet available
   - Beta version of config import in SonarCloud
 - `sonar-audit` a couple of new audit problems on permission templates (with no permissions, with no or wrong regexp)
+- Removed calls to all APIs deprecated with 10.x, used their up-to-date replacement instead
 
 # Version 3.3