gem5 cpu types: improve header structure

README.adoc

@@ -12186,9 +12186,11 @@ gem5 has a few in tree CPU models for different purposes.
 
 In fs.py and se.py, those are selectable with the `--cpu-type` option.
 
-TODO are there any public performance correlations between those models and real cores? The information to make accurate models isn't generally public for non-free CPUs, so either you must either rely vendor provided models or on experiments/reverse engineering.
+The information to make accurate models isn't generally public for non-free CPUs, so either you must either rely vendor provided models or on experiments/reverse engineering.
 
-==== gem5 BaseSimpleCPU
+==== List gem5 CPU types
+
+===== gem5 BaseSimpleCPU
 
 Simple abstract CPU without a pipeline.
 
@@ -12209,7 +12211,7 @@ Caches do make a difference here of course, and lead to much faster memory retur
 
 <<gem5-kvm,KVM CPUs>> are an alternative way of fast forwarding boot when they work.
 
-==== gem5 MinorCPU
+===== gem5 MinorCPU
 
 Generic in-order core that does not model any specific CPU.
 
@@ -12245,7 +12247,7 @@ ____
 +
 Implemented by Pierre-Yves Péneau from LIRMM, which is a research lab in Montpellier, France, in 2017.
 
-==== gem5 DeriveO3CPU
+===== gem5 DeriveO3CPU
 
 Generic out-of-order core. "O3" Stands for "Out Of Order"!