Update company values

Created by: nicksnyder

It is important to have clear and inspiring values as we grow. The current documentation of our values is sparse and could be improved. This is my attempt to do so.

We value being open and transparent. I added this as a core value and removed the other separate page to reduce duplication.

We value people. I added qualities of a successful teammate at Sourcegraph, which is the result of the content and comments on RFC 126. Please read that RFC for more context.

We value progress. I added more context on what that means at Sourcegraph.

I removed journey because the meaning is not clear. I think it had weird overlap between both people and progress that caused confusion.

We value being bottoms-up and delegating ownership. The best descriptor that I could think of for this was "servant leadership."

I would appreciate feedback from anyone and everyone on the team. We all own our values, I am merely a steward of the team to document them. Do these values and qualities resonate with you? Is there anything missing?