Update CODEOWNERS (#803)

As discussed in #791 with Rene: he requested to be replaced as code owner. I added instead the three regular code owners until further notice. Additionally, I have added our private GitHub dev account (account used for this PR) as a code owner for the website and shared folder, enabling quicker fixes, such as typos and similar issues.

CODEOWNERS

@@ -1,17 +1,16 @@
 # See https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
 
-/ui/ [email protected]
-.github/workflows/ui.yml [email protected]
-
 firebase.json [email protected] [email protected]
 firestore.rules [email protected] [email protected]
 package.json [email protected] [email protected]
 storage.rules [email protected] [email protected]
 
 admin/ [email protected] [email protected] [email protected]
 functions/ [email protected] [email protected] [email protected]
-shared/ [email protected] [email protected] [email protected]
+shared/ [email protected] [email protected] [email protected] [email protected]
 recipients_app/ [email protected] [email protected] [email protected]
-website/ [email protected] [email protected] [email protected]
+website/ [email protected] [email protected] [email protected] [email protected]
+ui/ [email protected] [email protected] [email protected]
+.github/workflows/ui.yml [email protected] [email protected] [email protected]
 
 *.md [email protected] [email protected] [email protected]