docs: update README.md on known issues and contributors
docs: update README.md on known issues and contributors

camunda/camunda-cockpit-plugin-statistics,camunda/camunda-cockpit-plugin-statistics,nagyistoce/camunda-cockpit-plugin-statistics,nagyistoce/camunda-cockpit-plugin-statistics,nagyistoce/camunda-cockpit-plugin-statistics,camunda/camunda-cockpit-plugin-statistics