links in tutorials are not working

[thomasrobiglio]

This was expected as I had written by hand the links. I will list them here and open a PR soon.

• [x] 5 mins -> focus tutorial on plotting
• [x] stats package paga -> focus tutorial on stats
• [x] xgi.stats.MultiDiEdgeStat -> focus tutorial on stats
• [x] ... all the classes in the stats package point to the tutorial, there should be 8 of them in total
• [x] ... all the modules in the stats package point to the tutorial on stats, there should be 4 of them
• [x] stats landing page -> focus tutorial on stats
• [x] ... views same as stats (see above)
• [x] Hypergraph class -> focus tutorial on statistics
• [x] DiHypergraph class -> focus tutorial on statistics

let me know if you happen to find others

[nwlandry]

I'm pretty sure that I addressed most of the link issues with #487, but it would be good to double-check what I did.

[thomasrobiglio]

Thank you very much @nwlandry, I have checked: all the non-functioning links that are listed are now ok. closing this.