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

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

Author: kesselb

.github/CODEOWNERS

@@ -70,10 +70,12 @@ ResponseDefinitions.php @provokateurin
 /lib/public/UserStatus              @nickvergessen
 
 # Groupware
-/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
+/build/integration/dav_features/caldav.feature   @st3iny @SebastianKrupinski @tcitworld
+/build/integration/dav_features/carddav.feature  @hamza221 @SebastianKrupinski
+/lib/private/Calendar                            @st3iny @SebastianKrupinski @tcitworld
+/lib/private/Contacts                            @hamza221 @SebastianKrupinski
+/lib/public/Calendar                             @st3iny @SebastianKrupinski @tcitworld
+/lib/public/Contacts                             @hamza221 @SebastianKrupinski
 
 # Personal interest
 */Activity/*                        @nickvergessen