Add a header with a nav bar

[Nutlope]

Nav bar should contain "Home, "Github" that links to GitHub, & maybe jobs once the job board is up

[omarouhra]

Let me know if this is what you mean! the Github link is for your personal GitHub account or for the "whatisdevrel" repo? Thanks

[Nutlope]

Exactly what I mean, thanks! The GitHub link should be for this repo. Gonna hold off on adding this header till I do the job board though