add example doc

README.md

@@ -16,5 +16,26 @@
 ## Examples
 
 ```ts
-// TODO
+import { init, MongoClient } from "https://deno.land/x/mongo/mod.ts";
+
+// Initialize the plugin and specify the binary release version (because the binary currently has no idea how to associate the version in ts and the binary)
+await init("0.1.0");
+
+const client = new MongoClient();
+client.connectWithUri("mongodb://localhost:27017");
+
+const db = getClient().database("test");
+const users = db.collection("users");
+
+// insert
+const insertId = await users.insertOne({
+  username: "user1",
+  password: "pass1"
+});
+
+// findOne
+const user1 = await users.findOne({ _id: insertId });
+
+// deleteOne
+const deleteCount = await users.deleteOne({ _id: insertId });
 ```