Minor style improvements and optional github profile

• Minor improvements of spacings (e.g. using tikz to place the applicant's photo)
• Footer in super-dark gray (instead of black) to draw focus on main document

Motivation environment and Appendix list

• Added an environment to write a motivational statement in (may be relevant for university and internship applications)
• Added an appendix list that is automatic like a TOC, including hyperlinks

Initial release

All that was done before moving to github, now polished:

• Basic setup and page format
• Correspondence environment
• Curriculum Vitae environment
• Appendix
• Properly licensed and documented