feat: switch theme to risotto and update config

- Add risotto theme as submodule
- Update hugo.yaml with new theme configuration
- Adjust menu URLs to be absolute paths
- Simplify makefile by removing redundant prep steps
- Update copyright notice and author info
- Remove old theme-specific CSP settings

makefile

@@ -5,11 +5,11 @@ default: build
 prep:
 	git submodule foreach --recursive bash -c "git checkout \$$(git remote show origin | grep HEAD | sed 's/.*\: //'); git pull"
 
-build: prep
+build:
 	/usr/bin/env bash version.sh
 
 deploy:
 	/usr/bin/env bash deploy.sh
 
-run: prep
+run:
 	hugo server