docs: add Installation section to metrics-centralization-points README (#22036)
* docs: add Installation section to metrics-centralization-points README Add clear installation guidance for Netdata Parents, addressing discoverability gap for users asking how to install a Parent. The section explicitly states that a Parent is a regular Netdata Agent and provides the kickstart.sh command with links to configuration documentation. * docs: replace inline kickstart example with installation link Replace inline kickstart command example with a link to the installation documentation to avoid maintaining duplicated installation instructions that can become outdated. * Apply suggestions from code review Co-authored-by: Fotis Voutsas <fotis@netdata.cloud> * Apply suggestions from code review Co-authored-by: Fotis Voutsas <fotis@netdata.cloud> * Upgrade Python version from 3.9 to 3.10 --------- Co-authored-by: nedi-app[bot] <bot@netdata.cloud> Co-authored-by: Fotis Voutsas <fotis@netdata.cloud>