Add missing dashes to descriptions of flags (#5812)
Add missing dashes to descriptions of flags (#5812)

Config and set flags had misleading descriptions that contained examples with one dash before the flag instead of two.

Co-authored-by: Bogdan Drutu <3f8e17047c2434e5c82a61403e56b9ef3e226d99@gmail.com>
open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector,open-telemetry/opentelemetry-collector