DX: Explain the Google Page Rank metric

[staabm]

first let me say, thanks for the great tool!

the home-screen of the report shows me classes sorted by google page rank

it would be great to have a few explaining words in this area. something along the lines:

• what is the class-rank is trying to tell me?
  • lower is better (?)
• what is a maintainability index?
  • highter is better (?)
• which facts are taken into consideration for this table - so, how to improve my scores - is it about class relations? properties? complexity?

I dont know what the table is trying to tell me, so the above suggestions might not be correct as far as the metric is concerned. please take them as a example

[staabm]

for reference, the "Maintainability / Complexity" visualization is doing a great job in explaining what is shown and what the impact is

[Halleck45]

Thanks for your help @staabm ! Feedbacks are really very welcome. I hope that's better now with #420