suggestion: coverage explorer

[iuioiua]

I suggest adding a new "Coverage" tab to package pages. The subdirectory would act as an explorer for test coverage, which most devs should be familiar with. It could be generated from a provided lcov-formatted file. Perhaps some inspiration could be taken from deno coverage --html.

I understand that this may be out-of-scope for JSR. But if it's not, it'd simplify the efforts that a dev would usually put toward setting up a third-party test coverage service that does this (that is, for someone who only wants an explorer and not the other features).