Suggestion. add "my notes" section to each challenge

Contributors
#1

feature: people can take their own notes on pages for their own use.

  • pros: people more likely to come back again and again for reference purposes.
  • cons: more database entryies to handle.
#2

you can keep notes as comments

/*
 * used multiple test calls at first to pass
 * found single regex later
*/
function telephoneCheck(str) {
}
#3