projects.html: Add link for project reports
projects.html: Add link for project reports

No link was provided on [projects](https://projects.coala.io/)
page to visit the past years GSoc projects reports. This commit
adds a link to visit that page. Link can be found just below the
search bar.
Fixes #683

coala/projects,coala/projects,coala/projects,coala/projects,coala/projects