Rename chart-testing-action

[tylerauerbeck]

Since as of v2 this seems to just be a wrapper for the installation of chart-testing, would it be better to rename this something like setup-chart-testing? This may reduce some confusion about what the action does in the long run.

[cpanato]

@unguiculus @davidkarlsen @scottrigby for thoughts

[davidkarlsen]

Hmmm, I tend to agree that the name would be more meaningful, I just wonder how much it will break. I know that renaming repos will allow for redirects, but does that work well with actions too?

Also, there will be docs to update, as well as the demo-action repo.

If this is easy to do and can be done without much disruption I'm in, but I'd like some comments on that before we rush to do it.