Ping page has almost no info

[wlach]

This issue is intended as an onboarding task for potential outreachy applicants. Please do not work on it unless you have completed the initial qualification task and it has been assigned to you.

We show only a tiny subset of the data related to the ping on the ping page right now. You can see an example of markdown documentation which more fully represents the metadata we have here:

https://github.com/mozilla/mozregression/blob/master/docs/glean/metrics.md#pings

The code that needs to be modified is here:

https://github.com/mozilla/glean-dictionary/blob/main/src/pages/PingDetail.svelte

All the information we want to display should already be extracted. If you have the server running locally, go to e.g.:

http://localhost:5000/data/mozregression/pings/usage.json

This is the dataset corresponding to:

http://localhost:5000/#!/apps/mozregression/pings/usage

Don't worry about styling the component too much-- can just use a table for now (like we do in the table view already: http://localhost:5000/#!/apps/mach/tables/usage)