docs: added some notes for running tools locally

docs/dev_notes.md

@@ -0,0 +1,40 @@
+# How to run the UI
+
+We set this up so it is hosted as a huggingface space. Each commit to `main` triggers a push and a rebuild on their servers.
+
+For local testing, assuming you have all the required packages installed in a
+conda env or virtualenv, and that env is activated:
+
+```
+cd src
+streamlit run main.py
+```
+Then use a web browser to view the site indiciated, by default: http://localhost:8501
+
+# How to build and view docs locally
+
+We have a CI action to presesnt the docs on github.io. 
+To validate locally, you need the deps listed in `requirements.txt` installed. 
+
+Run
+```
+mkdocs serve
+```
+And navigate to the wish server running locally, by default: http://127.0.0.1:8888/
+
+This automatically watches for changes in the markdown files, but if you edit the 
+something else like the docstrings in py files, triggering a rebuild in another terminal
+refreshes the site, without having to quit and restart the server.
+```
+mkdocs build -c
+```
+
+
+
+# Set up a venv
+
+(standard stuff)
+
+# Set up a conda env
+
+(Standard stuff)

mkdocs.yaml

@@ -35,7 +35,8 @@ nav:
       - Logging: st_logs.md
       - Tab-rendering fix (js): fix_tabrender.md
 
-
-
     - Development clutter:
       - Demo app: app.md
+    
+  - How to contribute:
+    - Dev Notes: dev_notes.md