Add custom annotation for decreasing arguments

added To Do label

added Doing label and removed To Do label

mentioned in commit 33099bd0

mentioned in commit 1471313e

mentioned in commit 7a3c9f3e

mentioned in commit c3aab4a5

mentioned in commit 9144b50c

mentioned in commit 2fa36c82

mentioned in issue #18

mentioned in commit dd127542

mentioned in commit 4878414c

added Review label and removed Doing label