Update and rename build.sc to build.mill (#321)

lihaoyi · web-flow · commit d1003d4ed1be · 2024-10-24T08:57:52.000+08:00
diff --git a/build.mill b/build.mill
@@ -1,3 +1,4 @@
+package build
 import mill._
 import scalalib._
 import scalajslib._
