Add release instruction to readme (#169)

**Legal Acknowledgement**\
By contributing to this software project, I agree my contributions are
submitted under the BSD license.
I represent I am authorized to make the contributions and grant the
license.
If my employer has rights to intellectual property that includes these
contributions,
I represent that I have received permission to make contributions and
grant the required license on behalf of that employer.

Author: jalving

README.rst

@@ -151,6 +151,12 @@ OMLT uses `just <https://github.com/casey/just>`_ to manage development tasks:
 * ``just dev-gpu`` same as ``dev`` but with GPU support
 * ``just docs`` to build the documentation
 
+OMLT also includes a workflow for publishing new releases. This workflow can be triggered by pushing a new tag with an updated version number: ::
+
+     git tag <version> # e.g. git tag v1.2.0
+     git push upstream --tags
+
+
 Contributors
 ============