Add build and allow dist

dist/util/index.d.ts

@@ -0,0 +1,20 @@
+/// <reference types="node" />
+import { readFileToStringDefaultEncoding, readFileToJson } from "./file.util"
+import {
+    assertNotNullOrUndefined,
+    assertNotNullOrUndefinedOrEmpty,
+    isNullOrUndefined,
+    isNullOrUndefinedOrEmpty,
+} from "./test.util"
+declare const stringToBuffer: (data: string | Buffer) => Buffer
+declare const bufferToString: (data: string | Buffer) => string
+export {
+    readFileToStringDefaultEncoding as readFileToString,
+    readFileToJson,
+    stringToBuffer,
+    bufferToString,
+    assertNotNullOrUndefined,
+    assertNotNullOrUndefinedOrEmpty,
+    isNullOrUndefined,
+    isNullOrUndefinedOrEmpty,
+}