[Update, v1.2] Create new Basketball event

Extracted comments to list changes from the JavaScript file
(basketball.js)

Changes:
- Added validation check for input only for score in the basketball_new
page

Assumptions:
  - Date, Time, Status, Winner does not have to be set
immediately. Can be edited later by user
  - Date and Time is provided
in a controlled input, hacking not considered
  - Only score is
validated