added: 'category' in problems fetch
added: encoding info
added: new get_problems function
Update the UI of problems page.
added: single-user problem fetch
changed: sample data format
added: rewritten problem.py
Merge branch 'local-testing' of github.com:starrify/CTF-Platform into local-testing
Add recaptcha ui into problems.
Merge branch 'local-testing' of github.com:starrify/CTF-Platform into local-testing
Make collapse shown acoording to anchor.
shorten the display time of recaptcha.
Add margin between flag input and submmit button.
changed: function structure in problem.py
added: scoreboard modal (without calculation of time penalty for now)
fixed: several bugs introduced in the previous commit
Merge branch 'local-testing' of github.com:starrify/CTF-Platform into local-testing
added: scoreboard
added: better approach of fetching problems from the db
changed: dealing with input encodings
fixed: typo