Add some basic comments to prometheus to navigate better
Add some basic comments to prometheus to navigate better

Example for a 4 socket system:
 # Core Counters Socket 0
 # Uncore Counters Socket 0
 # Core Counters Aggregate Socket 0
 # Core Counters Socket 1
 # Uncore Counters Socket 1
 # Core Counters Aggregate Socket 1
 # Core Counters Socket 2
 # Uncore Counters Socket 2
 # Core Counters Aggregate Socket 2
 # Core Counters Socket 3
 # Uncore Counters Socket 3
 # Core Counters Aggregate Socket 3
 # UPI/QPI Counters
 # Core Counters Aggregate System
 # Uncore Counters Aggregate System

opcm/pcm,opcm/pcm,opcm/pcm,opcm/pcm