Add link to doc.md
Add link to doc.md

AliyunContainerService/fluentd-pilot,BSWANG/fluent-pilot,bamboox/fluentd-pilot,AliyunContainerService/fluentd-pilot,AliyunContainerService/fluentd-pilot,BSWANG/fluent-pilot,BSWANG/fluent-pilot,bamboox/fluentd-pilot,bamboox/fluentd-pilot,bamboox/fluentd-pilot,AliyunContainerService/fluentd-pilot