metrics and monitoring: add info about picodata metrics
Follow-up for: !1710 (merged)
See also: #1430 (closed) #1759 (closed)
Doc pages to change: https://docs.picodata.io/picodata/devel/reference/metrics/
Edited by Вартан Бабаян
Follow-up for: !1710 (merged)
See also: #1430 (closed) #1759 (closed)
Doc pages to change: https://docs.picodata.io/picodata/devel/reference/metrics/