Add initial README (#2)

README.md

@@ -1,2 +1,31 @@
 # ec2-bastion-cdk
-Create bastion instances backed by an ASG
+
+Docs: https://isotoma.github.io/ec2-bastion-cdk/
+
+NPM: https://www.npmjs.com/package/ec2-bastion-cdk
+
+Source: https://github.com/isotoma/ec2-bastion-cdk
+
+## Example
+
+```typescript
+import { Ec2HaBastion } from 'ec2-bastion-cdk';
+
+// ...
+
+const bastion = new Ec2HaBastion(this, 'Bastion', {
+    vpc: myVpc,
+    allowedCidrs: [
+        '1.2.3.999',
+    ],
+    publicKeys: [
+        'ssh-ed225519 Abcdef123Xyz me@host',
+    ],
+    allowShell: true,
+});
+
+new route53.ARecord(this, 'BastionRecord', {
+    recordName: 'mybastion',
+    zone: myZone,
+    target: route53.RecordTarget,fromAlias(new route53Targets.LoadBalancerTarget(bastion.networkLoadBalancer)),
+});