Allow output dir to be provided
diff --git a/build.sh b/build.sh
index e50d85a..fc19680 100755
--- a/build.sh
+++ b/build.sh
@@ -2,5 +2,6 @@
 
 # Dummy build script
 
-test -d docs || mkdir docs
-date >docs/date.txt
+OUT=${1:?}
+test -d ${OUT} || mkdir ${OUT}
+date >${OUT}/date.txt