feat: add Getting started section to README (#8)

Author: ahanoff

README.md

@@ -1,9 +1,40 @@
 # AEMO.MDFF
 
 [![Build](https://github.com/ahanoff/aemo-mdff-net/actions/workflows/build.yaml/badge.svg)](https://github.com/ahanoff/aemo-mdff-net/actions/workflows/build.yaml)
+![NuGet Version](https://img.shields.io/nuget/vpre/AEMO.MDFF)
+![NuGet Downloads](https://img.shields.io/nuget/dt/AEMO.MDFF)
+![GitHub License](https://img.shields.io/github/license/ahanoff/aemo-mdff-net)
 
 Parser for Australian Energy Market Operator (AEMO) Meter Data File Format (MDFF) specification
 
+## Getting started
+
+Install Nuget package
+
+```shell
+dotnet add package AEMO.MDFF
+```
+
+Use Nem12Reader to parse csv file
+
+```csharp
+using AEMO.MDFF.NEM12;
+
+var nem12Reader = new Nem12Reader();
+await using var fs = new FileStream("nem12.csv", FileMode.Open, FileAccess.Read);
+await foreach (var r in nem12Reader.ReadAsync(fs, CancellationToken.None))
+{
+    switch (r)
+    {
+        case HeaderRecord { VersionHeader: var vh }:
+            Console.WriteLine(vh);
+            break;
+        case NMIDataDetailsRecord { NextScheduledReadDate: var nsrd }:
+            Console.WriteLine(nsrd.ToLongDateString());
+            break;
+    }
+}
+```
 
 ## References