Clarify are ticket branches are needed

I took out the text to the developer guide because it wasn't cleared why it matttered.

It's been pointed out that's for versions to be published

docs/technotes/migrate.rst

@@ -16,6 +16,7 @@ Getting started
 #. Make sure you have a Python 3.11 environment.
 
 #. Check out your technote repo and create a working branch.
+   Use a `ticket branch <https://developer.lsst.io/work/flow.html#ticket-branches>`__ if you want to preview your technote online.
 
 #. We have provided a `migration tool <#technote-migration-tool>`__ ():command:`documenteer technote migrate`) that converts your technote repository from the old framework to the new one.
    You should only be resorting to the `manual steps <#technote-migration-detailed>`__ if you have a problem with the tool or are in another non-typical situation such as a customized build process.