document commandline args for complement

Signed-off-by: strawberry <strawberry@puppygock.gay>

tests/complement/README.md

@@ -7,6 +7,10 @@ Have a look at [its repository](https://github.com/matrix-org/complement).
 ## How do I use it with Conduit?
 
 The script at [`../bin/complement`](../bin/complement) has automation for this.
-It takes a few command line arguments, you can read the script to find out what
-those are.
+It takes a few command line arguments:
 
+- Path to Complement's source code
+- A `.jsonl` file to write test logs to
+- A `.jsonl` file to write test results to
+
+Example: `./bin/complement "../complement" "logs.jsonl" "results.jsonl"`