Fixes the common HTML validation in files.

[kumars21]

Fixes the common HTML validation in files.

• app/templates/Leaderboard.html
• app/templates/home.html
• app/templates/login.html
• app/templates/profile.html @Manishv005 @nishandevkar @krishgoti2002 these are the files i fixes the common HTML validation rest all seems ok and not major if we ignore the jinja template validation or info . Pls have a look . I tested the application seems ok but try one.

[Manishv005]

All Good.