add example usage file

src/node/example.mjs

@@ -0,0 +1,65 @@
+/**
+ * Before using this file, run `npm run build-node`
+ *
+ * Run with `node --experimental-modules src/node/example.mjs` from proj root
+ */
+
+
+import chef from "./index";
+import {
+    setUnion,
+    toBase32,
+    fromBase32
+} from "./index";
+import OperationError from "../core/errors/OperationError";
+
+// All ops under the chef object.
+let result = chef.toBase32("input");
+
+/**
+ * Display
+ */
+
+// override .inspect so it prints the Dish value
+console.log(result); // => NFXHA5LU
+
+// toString override
+console.log(String(result)); // => NFXHA5LU
+
+// toValue override
+console.log(""+result); // => "NaN"
+console.log(3 + chef.fromBase32(chef.toBase32("32"))); // => 35
+
+/**
+ * Conversion
+ */
+
+// synchronous type conversion
+console.log(result.get("bytearray")); // => [ 78, 97, 78 ]
+
+console.log(result.get("number")); // => NaN
+
+/**
+ * Accepts normal input (with args in object) and dish (for chaining)
+ */
+
+// default args
+console.log(toBase32("something")); // => ONXW2ZLUNBUW4ZY=
+
+// override arg (doesnt have to be them all) - arg names are lenient,
+// e.g. would accept 'alphabet', 'Alphabet' & ignores whitespace
+console.log(toBase32("something", { alphabet: "A-S" })); // => ONLNB
+
+// Pass result of one op to another
+console.log(fromBase32(toBase32("66"))); // => "66"
+
+/**
+ * Errors
+ */
+
+// let all errors (even OperationErrors) bubble up
+try {
+    setUnion("1");
+} catch (e) {
+    console.log(e instanceof OperationError); // => true
+}