Add the possibility to have one badge for multiple years

[Graygzou]

I noticed this action was not currently able to combine many years at once inside a badge. To display it inside the github profile repository for example. So I started to adapt your script a little to do it.

It's only after doing it, that I realized issues #5 or #10 where already mentionning something like this.
Like you said in one of them:

Altough it should not add significant load it does still violate Eriks rule of only 1 request per 15min. I will strictly adhere to this rule.

My change cause this violation so I understand it might not fit your repository well.
I still create the PR just for visiblity.