asim: add comments for datadriven

This commit updates comments for a few options we added recently.

Epic: none
Release note: none

Author: wenyihu6

pkg/kv/kvserver/asim/tests/datadriven_simulation_test.go

@@ -37,18 +37,21 @@ import (
 //
 //   - "gen_load" [rw_ratio=<float>] [rate=<float>] [access_skew=<bool>]
 //     [min_block=<int>] [max_block=<int>] [min_key=<int>] [max_key=<int>]
-//     [replace=<bool>]
+//     [replace=<bool>] [cpu_per_access=<int>] [raft_cpu_per_write=<int>]
 //     Initialize the load generator with parameters. On the next call to eval,
 //     the load generator is called to create the workload used in the
 //     simulation. When `replace` is false, this workload doesn't replace
 //     any existing workload specified by the simulation, it instead adds it
 //     on top.The default values are: rw_ratio=0 rate=0 min_block=1
 //     max_block=1 min_key=1 max_key=10_000 access_skew=false replace=false
+//     cpu_per_access=0 raft_cpu_per_write=0
 //
 //   - "gen_cluster" [nodes=<int>] [stores_per_node=<int>]
+//     [store_byte_capacity=<int>] [node_cpu_rate_capacity=<int>]
 //     Initialize the cluster generator parameters. On the next call to eval,
 //     the cluster generator is called to create the initial state used in the
-//     simulation. The default values are: nodes=3 stores_per_node=1.
+//     simulation. The default values are: nodes=3 stores_per_node=1
+//     store_byte_capacity=256<<32, node_cpu_rate_capacity=0.
 //
 //   - "load_cluster": config=<name>
 //     Load a defined cluster configuration to be the generated cluster in the