readme: add screenshot

README.md

@@ -4,32 +4,10 @@ Stop flushing your performance down the drain.
 
 ## Overview
 
-This Linux-only command line tool compares the performance of multiple commands
+This command line tool uses Linux's `perf_event_open` functionality to compare the performance of multiple commands
 with a colorful terminal user interface.
 
-Example output (colors are lost here):
-
-```
-$ zig-out/bin/poop 'zig-out/bin/poop -h' 'hyperfine -h'
-Benchmark 1 (5989 runs): zig-out/bin/poop -h:
-  measurement      mean ± σ               min … max                  delta
-  wall_time        156.464us ± 50.149us   114.726us … 656.436us      0%
-  peak_rss         395K ± 96K             225K … 565K                0%
-  cpu_cycles       28710 ± 3576           24078 … 115760             0%
-  instructions     24540 ± 0              24540 … 24542              0%
-  cache_references 469 ± 51               328 … 898                  0%
-  cache_misses     32 ± 66                0 … 389                    0%
-  branch_misses    330 ± 105              197 … 3980                 0%
-Benchmark 2 (2792 runs): hyperfine -h:
-  measurement      mean ± σ               min … max                  delta
-  wall_time        1.004ms ± 225.862us    813.217us … 2.283ms        💩+542.1%
-  peak_rss         3M ± 101K              3M … 4M                    💩+845.4%
-  cpu_cycles       1292937 ± 181343       1171450 … 2589993          💩+4403.4%
-  instructions     1804252 ± 977          1803273 … 1809868          💩+7252.2%
-  cache_references 40985 ± 1237           35258 … 52664              💩+8641.6%
-  cache_misses     5867 ± 7613            137 … 24350                💩+18101.1%
-  branch_misses    12419 ± 338            11501 … 13554              💩+3666.1%
-```
+![image](https://github.com/andrewrk/poop/assets/106511/c4f4d4f1-c25e-473c-bdd2-95a0692d280f)
 
 ## Usage