Make it easy to deploy and test your own precompile

[gatesyp]

I noticed that was the first thing hagen did when he played with subnets for the first time (in the third image):

https://twitter.com/0xhagen/status/1619742515011387394?s=46&t=mGyrPwkM7rvDqtkAiLaCOg

(Maybe just documenting it as use case?)