Update README.md: fix docs update workflow

Author: alexbozhenko

README.md

@@ -233,12 +233,20 @@ as follows:
 git clone https://github.com/nats-io/nats.py
 cd nats.py
 git clone https://github.com/nats-io/nats.py --branch docs --single-branch docs
+cd docs
 pipenv install --dev sphinx sphinx_autodoc_typehints myst_parser furo pygments 
 pipenv shell
 make html
+# preview the changes:
 make serve
 ```
 
+If you are happy with the changes, make a PR on the docs branch:
+```
+make publish
+git add docs
+```
+
 ## License
 
 Unless otherwise noted, the NATS source files are distributed under