hackweek: Relay dashboard (#2422)

Add Web UI Dashboard to Relay. 

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Co-authored-by: Oleksandr Kylymnychenko <oleksandr@sentry.io>
Co-authored-by: Oleksandr <1931331+olksdr@users.noreply.github.com>

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Add `view_names` to `AppContext` ([#2344](https://github.com/getsentry/relay/pull/2344))
 - Tag keys in error events and transaction events can now be up to `200` ASCII characters long. Before, tag keys were limited to 32 characters. ([#2453](https://github.com/getsentry/relay/pull/2453))
 - The Crons monitor check-in APIs have learned to accept JSON via POST. This allows for monitor upserts by specifying the `monitor_config` in the JSON body. ([#2448](https://github.com/getsentry/relay/pull/2448))
+- Add an experimental web interface for local Relay deployments. ([#2422](https://github.com/getsentry/relay/pull/2422))
 
 **Bug Fixes**: