Modify build script and prettier config type (.prettierrc to .prettierrc.mjs

.prettierrc.mjs

@@ -0,0 +1,20 @@
+import { readFileSync } from "fs";
+let localPrettierConfig = {};
+
+try {
+    const localConfig = readFileSync(".prettierrc.local", "utf-8");
+    localPrettierConfig = JSON.parse(localConfig);
+    console.log("Using local Prettier config from .prettierrc.local");
+} catch (e) {
+    // no local config
+}
+const prettierConfig = {
+    trailingComma: "es5",
+    tabWidth: 4,
+    printWidth: 120,
+    semi: true,
+    endOfLine: "cr",
+    ...localPrettierConfig,
+};
+
+export default prettierConfig;