generate rollup and webpack templates from a single unified branch

_template/build-pkg.js

@@ -0,0 +1,13 @@
+const fs = require('fs');
+
+const type = process.argv[2];
+
+const pkg = require('../package_template.json');
+for (const key in pkg['merge-configs'][type]) {
+	Object.assign(pkg[key], pkg['merge-configs'][type][key]);
+}
+delete pkg['merge-configs'];
+fs.writeFileSync(
+	__dirname + '/../package.json',
+	JSON.stringify(pkg, null, '  ') + '\n'
+);