Collect summary statistics on how many people we reached

[jspaaks]

e.g. the total number of stars, followers, forks, separated into two groups: within eScienceCenter repos, and outside repos.

[fdiblen]

Releated to #23

[fdiblen]

Collected statistics are here:
https://nlesc-my.sharepoint.com/:x:/g/personal/f_diblen_esciencecenter_nl/EdIWf9WVzkRDlIzvvOVph7UB4rh7FuAwAOFCETLS99L15w