chore(codeowners): add codeowners for calendar and contacts api

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

Author: kesselb

.github/CODEOWNERS

@@ -70,8 +70,10 @@ ResponseDefinitions.php @provokateurin
 /lib/public/UserStatus              @nickvergessen
 
 # Groupware
-/build/integration/dav_features/caldav.feature    @miaulalala @st3iny @SebastianKrupinski
-/build/integration/dav_features/carddav.feature   @miaulalala @st3iny @SebastianKrupinski
+/build/integration/dav_features/caldav.feature		@st3iny @SebastianKrupinski @tcitworld
+/build/integration/dav_features/carddav.feature		@hamza221 @SebastianKrupinski
+/lib/public/Calendar					@st3iny @SebastianKrupinski @tcitworld
+/lib/public/Contacts					@hamza221 @SebastianKrupinski
 
 # Personal interest
 */Activity/*                        @nickvergessen