nix: add example on how to use a library locally #125

Loadtest Results

param	v12.0.2	head	main
bytes_in.mean	1008	1008	1007
bytes_in.total	27629867	26915604	28101416
bytes_out.mean	3849	3848	3849
bytes_out.total	105541040	102789380	107361560
duration	60000521844	60006896675	60000565849
latencies.50th	970190	970588	953020
latencies.90th	2167937	2175631	2120044
latencies.95th	13933465	14840632	13842046
latencies.99th	14644186	15183877	14388663
latencies.max	205288890	26462906	26359440
latencies.mean	2187253	2245576	2149841
latencies.min	152254	153095	152885
latencies.total	59967923397	59979349787	59971984145
rate	457	445	465
requests	27417	26710	27896
status_codes.200	14955	14570	15216
status_codes.201	4986	4856	5072
status_codes.204	7476	7284	7608
success	1	1	1
throughput	457	445	465
wait	1767356	793876	171480