Clarifying goals

Following discussions on Slack, I'm proposing this MR to clarify our goals and current project progress status. I merged in commits from #8 (closed) too so as to address the merge conflict and preserve history. The front page now clarifies what Cinc is and a goals.md has been added to the menu's root. I've also adjusted our disclaimers to mention we're confident in Cinc Client, but the rest should still be approached with care.

In addition to the clarifications, I've also reworked some vocabulary to minimize all forms of liabilities while still providing assurances. I've also added some nudges to indirect contributors, like CT and the folks from Biome. There's a new contributing.md page with some very broad (and therefor hopefully futureproof) statements about how to help. I've added a blog post celebrating our review by Chef. Finally, I added to the about page stuff which I hope would address concerns such as those raised by @aaronlippold . Thoughts?