[docs] Add status header for Riak receiver (#11103)
[docs] Add status header for Riak receiver (#11103)

* [docs] Add status header for Riak receiver

* Apply suggestions from code review

Co-authored-by: Daniel Jaglowski <17cc37e4ca6cfeebfa7364093519bf4e9ef9b450@gmail.com>

Co-authored-by: Daniel Jaglowski <17cc37e4ca6cfeebfa7364093519bf4e9ef9b450@gmail.com>
open-telemetry/opentelemetry-collector-contrib,open-telemetry/opentelemetry-collector-contrib