docs: add docs pointing to the code used to generated the plots

specs/src/specs/resource_pricing.md

@@ -211,6 +211,8 @@ dot over the execution lifecycle of a given transaction. The y-axis is units of
 gas and the x-axis is cumulative gas consumption. The legend shows which color
 indicates what the cause of the gas consumption was.
 
+This code used to trace gas consumption can be found in the `tools/gasmonitor` of the branch for [#2131](https://github.com/celestiaorg/celestia-app/pull/2131), and the script to generate the plots below can be found [here](https://gist.github.com/evan-forbes/948c8cf574f2f50b101c89a95ee1d43c) (warning: this script will not be maintained).
+
 ### MsgSend
 
 Here we can see the gas consumption trace of a common send transaction for