Update domain from pyhpc.io to pyhpc.org

- Change CNAME record to pyhpc.org
- Update site URL in publishconf.py
- Update README references to new domain

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: aterrel

README.md

@@ -1,7 +1,7 @@
-www.pyhpc.io
+www.pyhpc.org
 ============
 
-This repository contains the landing page and blog for www.pyhpc.io. 
+This repository contains the landing page and blog for www.pyhpc.org. 
 
 ## Contributing
 

content/CNAME

@@ -1 +1 @@
-pyhpc.io
+pyhpc.org

publishconf.py

@@ -11,7 +11,7 @@
 from pelicanconf import *
 
 # If your site is available via HTTPS, make sure SITEURL begins with https://
-SITEURL = 'https://www.pyhpc.io'
+SITEURL = 'https://www.pyhpc.org'
 RELATIVE_URLS = False
 
 FEED_ALL_ATOM = 'feeds/all.atom.xml'