Added testing ability

For the full details, see patches/README.md :-)

patches/README.md

@@ -1,9 +1,35 @@
-# The ziglings/patches Directory
+# No Peeking! :-)
 
-This is how ziglings is tested.
+Welcome to the ziglings/patches directory. This is how ziglings is tested.
 
-The patches fix the broken exercises so that they work again.
+The patches fix the broken exercises so that they work again, which means the
+answers are here, so no peeking!
 
-No peeking! :-)
+## Éowyn
+
+A Bash shell script named `eowyn.sh` dwells here. She heals the little broken
+programs and places them in a `healed` directory, which is not committed to the
+repo.
+
+```bash
+$ ./eowyn.sh
+```
+
+(If you invoke her from elsewhere, she'll come here to ply her trade.)
+
+The `build.zig` build script at the heart of Ziglings has a top-secret option
+which tells it to test from the `patches/healed/` dir rather than `exercises/`:
+
+```bash
+$ zig build -Dhealed [step]
+```
+
+Éowyn tests all healed programs using this secret option.
+
+
+## Gollum
+
+Another Bash shell script named `gollum.sh` may also be found. He snatches the
+original answers and stows them in his secret answers stash. If you leave him
+alone, he'll leave you alone.
 
-(Further tooling and explanation goes here.)