Update README.md (#2338)
Update README.md (#2338)

A small edit for clarity in the Recommended Processors section.
open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector-contrib,open-telemetry/opentelemetry-collector-contrib