link authors to their github profile

[arhimede]

Feature Request

Q	A
New Feature	yes
RFC	yes/no
BC Break	yes/no

Summary

each author should be linked to their github profile

[arhimede]

refactor this pages
https://new.dotkernel.com/author/florin-bidirean/

to keep the name
remove the email
add link to their github profile

[arhimede]

remove email and bio columns from DB
add github column