Update README branding and referral link

Replace header branding to 'NX AI', remove the redundant 'I_Python' section and duplicate sentence, and simplify the referral query parameter from `s=python-nx-ai` to `s=python`. Minor copy edits to the intro for consistency.

Author: goldlabelapps

README.md

@@ -1,12 +1,10 @@
-# ![NextJS](/app/static/repoicon.png) <NEW> I_Python
+# ![NX AI](/app/static/repoicon.png) <NEW> NX AI
 
 > Python with FastAPI using Postgres & tsvector. Open Source, production ready Python FastAPI/Postgres app. [GitHub](https://github.com/goldlabelapps/python-nx-ai) | [NX-AI onrender](https://nx-ai.onrender.com)
 
-## I_Python
-
 > Python with FastAPI using Postgres & tsvector. 
 
-Open Source, production ready Python FastAPI/Postgres app for [NX](https://goldlabel.pro?s=python-nx-ai)
+Open Source, production ready Python FastAPI/Postgres app for [NX](https://goldlabel.pro?s=python)
 
 ```sh
 uvicorn app.main:app  --reload