distribution: record goals we've completed

Created by: slimsag

I went back and revisited the goals we set out to achieve earlier this year in Q1 and found a lot of interesting info that made me quite proud of how much progress we've made, I think we could communicate this to others (and potential candidates, etc.) even better if we record this information.

I have created a doc where we can record past goals we've completed, and retro-fitted it with all past goals I am aware of, excluding some time ranges I couldn't easily pull together (mostly because our goals were muddied during that time.)

If you can think of major milestones/goals we achieved, or helped play a role in any of the ones here, please add that!

Stacked on top of https://github.com/sourcegraph/about/pull/1973