Document Inbound Filters and Session Replay

[bruno-garcia]

We partially resolved the inbound filter for replay feature:

• Replay: Allow Inbound Filters to apply to replays sentry#44700

In that ticket we mention what types of filters are already active. We now need to add that information to the docs, also mentioning how it affects the Stats page since the Accepted <> Filtered graph looks quite different due to how we calculate the two. Context in the linked issue above.