Use sh instead of bash, works on vanilla alpine

build.sh

@@ -1,13 +1,13 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
-# remove previous build leftovers
+# Remove previous build leftovers
 rm -rf ./_site
 
-# build, results are in ./_site
+# Build, results are in ./_site
 deno task build
 
-# put fonts in place
+# Put fonts in place
 cp -r ./fonts ./_site/
 
-# clean up
+# Clean up
 rm -rf ./_site/README