Rename 'Gift access' to 'Guest access' — pure terminology rename, page and nav moved to guest-access.md

mkdocs.yml

@@ -69,7 +69,7 @@ theme:
 nav:
   - Home: README.md
   - Getting started: getting-started.md
-  - Gift access: gift-access.md
+  - Guest access: guest-access.md
   - Models: models.md
   - API access: api-access.md
   - Energy & carbon: energy.md