Update build script and contribution guide

build

@@ -1,14 +1,15 @@
 #!/bin/bash
 
 cd sources
-npm install
 
 case "$1" in
     all)
+        npm clean-install
         nprm run all
         ;;
     act)
         # Build and copy outputs to the dist directory
+        npm install
         npm run build
         cd ..
         cp -r sources/dist .
@@ -17,7 +18,12 @@ case "$1" in
         # Revert the changes to the dist directory
         git co -- dist
         ;;
+    init-scripts)
+        cd test/init-scripts
+        ./gradlew check
+        ;;
     *)
+        npm install
         npm run build
         ;;
 esac