Add hint to build instructions

TheAssassin · web-flow · commit d5510bd09006 · 2022-04-17T17:19:22.000+02:00
diff --git a/BUILD.md b/BUILD.md
@@ -1,5 +1,7 @@
 # How to build AppImageLauncher
 
+**Note:** This file was contributed by a user. It may be out of date.
+
 If there are no pre-build binaries for your platform you may consider to build AppImageLauncher yourself. Please follow these instructions.
 
 
