* Update metrics.md

* Updated metrics.md and configuration.md

* Added links to data sources

* Update metrics.md

* Update docs/sources/administration/metrics.md

Co-Authored-By: Carl Bergquist <carl@grafana.com>

Co-authored-by: Carl Bergquist <carl@grafana.com>
Co-authored-by: bergquist <carl.bergquist@gmail.com>