Docs: Add very basic example in WIP Quick Guide.

Author: microbit-carlos

.gitignore

@@ -14,7 +14,6 @@ lib-fesm
 fesm
 umd
 bundles
-docs
 dist
 
 ## this is generated by `npm pack`

docs/quick-guide.md

@@ -0,0 +1,30 @@
+---
+layout: default
+title: Quick Guide
+nav_order: 2
+---
+
+# Quick Guide
+
+## ES5 UMD Bundle
+
+```js
+var universalHex = microbitUh.createUniversalHex([
+  {
+    hex: intelHexString1,
+    boardId: 0x1,
+  },
+  {
+    hex: intelHexString2,
+    boardId: 0x2,
+  },
+]);
+
+if (microbitUh.isUniversalHex(intelHexStr)) {
+  var separatedBinaries = microbitUh.separateUniversalHex(intelHexStr);
+}
+separatedBinaries.forEach(function (hexObj) {
+  console.log(hexObj.boardId);
+  console.log(hexObj.hex);
+});
+```