inadequate example config in README.adoc

[mozai]

README.adoc says "Systemd service uses following configuration file for global and collectors related configurations" with a
config file that only mentions two collectors: gluster_ps and gluster_brick , but reading the source code I found:

• gluster_brick
• gluster_brick_status
• gluster_peer_counts
• gluster_peer_info
• gluster_ps
• gluster_volume_counts
• gluster_volume_heal
• gluster_volume_profile
• gluster_volume_status

Reading the Makefile I found it copies extras/conf/gluster-exporter.toml.sample to /usr/local/etc/gluster-exporter/gluster-exporter.toml , and that .sample file lists the above collectors. Would really help if the README.adoc mentioned that file is the example that should be used, not what's in the README.adoc.

Would also be nice if docs/metrics.adoc groups the metrics by which collector provides them.