Add a graph for languages used, provided github repos

[ivanpeng]

Whether it's from the github linking on AoC, or manually, or both, given a github URL that is the AoC code for that user, we can generate a graph (bar? pie?) on languages used. Github API can be used if we find out the remote URL.

[bewuethr]

If the entire repo is dedicated to AOC:

gh repo view '{owner}/{repo}' --json primaryLanguage