docs: use <details> tag for troubleshooting section

Author: vladholubiev

readme.md

@@ -67,10 +67,13 @@ it('should insert item into table', async () => {
 
 ## Troubleshooting
 
-### `UnknownError: Not Found`
+<details>
+<summary>`UnknownError: Not Found`</summary>
 
 Perhaps something is using your port 8000.
 
+</details>
+
 ## Read
 
 - [dynamodb-local](https://github.com/rynop/dynamodb-local)