fix: typo in GitHub Pages casing

Author: brunocassol

README.md

@@ -2,7 +2,7 @@
 
 This is the code for https://brunocassol.com which is hosted by Github Pages.
 
-It is neatly generated by exporting a Joplin's notebook, processed using `node joplin_to_github.js` and then pushed to this repo which is served by GitHub pages.
+It is neatly generated by exporting a Joplin's notebook, processed using `node joplin_to_github.js` and then pushed to this repo which is served by GitHub Pages.
 
 The process is described here: https://brunocassol.com/blog/2023-02-08-How-I-blog-using-joplins-EXPORT-HTML-Di.html