The scores are lightly processed from their internal representation.
Example usage:
```
$ yarn backend;
$ node bin/sourcecred.js load sourcecred/sourcecred
$ node bin/sourcecred.js scores sourcecred/sourcecred > scores.json
```
The data structure is as follows:
```js
export type NodeOutput = {|
+id: string,
+totalCred: number,
+intervalCred: $ReadOnlyArray<number>,
|};
export type ScoreOutput = Compatible<{|
+users: $ReadOnlyArray<NodeOutput>,
+intervals: $ReadOnlyArray<Interval>,
|}>;
```
Test plan: I added sharness tests at `sharness/test_cli_scores.t`.
In the past, we've used javascript tests for CLI commands. However,
those are pretty time-consuming to write, and are less robust than
simply running the command from bash. Check the snapshot for a sense of
what the new data format looks like. Also, the snapshot updater now
updates this snapshot too.
Relevant for #1047.
Thanks to @Beanow for feedback on the output format and design.
Thanks to @wchargin for help in code review.
88f736d180