Tie benchmarks more closely to perf analyzers

[chucker]

Right now, I see that there are some benchmarks for the performance analyzers, but they don't seem to match 1:1 and are hard to find. (Also, apparently most of them don't have their HTML output in the repo?)

It would be nice for the code of, say, DoNotUseElementAtAndElementAtOrDefaultAnalyzer.cs to point to which benchmarks cover it (e.g., ListIndexerVersusLinqElementAtBenchmarks.cs).

[Kavignon]

Hey @chucker Thanks for updating us about this.

This was a project born straight out of a hackathon week (4 days of development) and the rest of the efforts were geared towards making this project as OSS as possible.

We'll take your feedback and get these under wraps!