chore(docs): update readme(add description, example, license)

Author: yicr

README.md

@@ -1 +1,29 @@
 # AWS CodeConnections Host Custom Resource
+
+This AWS CDK Construct provides a custom resource (Lambda Function) to create a connection host for Self-Managed GitLab, which is not yet supported by CloudFormation. Additionally, even after creating the Host and the connection, authentication must be done via a browser.
+
+
+## Example
+
+```typescript
+import { RDSDatabaseAutoRunningStopStack } from '@gammarers/aws-codeconnections-host-custom-resource';
+
+const codeConnectionsHostCustomResource = new CodeConnectionsHostCustomResource(this, 'CodeConnectionsHost', {
+  name: 'gitlab.example.com', // required, connection host name (Minimum length of 1. Maximum length of 64.)
+  providerEndpoint: 'https://gitlab.example.com', // required, your provider endpoint (Minimum length of 1. Maximum length of 512.)
+  providerType: 'GitLabSelfManaged', // required, Bitbucket | GitHub | GitHubEnterpriseServer | GitLab | GitLabSelfManaged
+});
+
+// get host arn
+const hostArn = codeConnectionsHostCustomResource.getResponseField('HostArn');
+
+new codeconnections.CfnConnection(this, 'Connection', {
+  connectionName: 'example-gitlab-connection',
+  hostArn,
+});
+
+```
+
+## License
+
+This project is licensed under the Apache-2.0 License.