KFP - Updated the documentation regarding metrics (#2171) * [WIP] Updated the documentation regarding metrics * Resolved the feedback * Added an alternative python component example * Added a component.yaml example * Apply suggestions from code review Co-authored-by: 8bitmp3 <[email protected]> * Update content/en/docs/pipelines/sdk/pipelines-metrics.md Co-authored-by: 8bitmp3 <[email protected]> Co-authored-by: 8bitmp3 <[email protected]>