added an example

README.md

@@ -15,6 +15,8 @@ Your contributions are vital to keeping this repository valuable and up-to-date.
 1. **Submit a Pull Request (PR)**: Submit a PR to the main repository for review.
 2. **Edit the JSON directly** [here](https://github.com/bcnmy/aa-errors/edit/main/docs/errors.json) (be careful!).
 
+**NB: The 'regex' field is used to match a thrown error from the SDK to your KnownError, so please make sure it is a string unique to your error**
+
 #### Error Documentation Structure
 
 ```typescript
@@ -27,4 +29,20 @@ export type KnownError = {
 };
 ```
 
+#### Example:
+
+```
+{
+    "name": "SmartAccountInsufficientFundsError",
+    "regex": "aa21",
+    "description": "You are not using a paymaster, and the sender address did not have enough native tokens to cover the gas costs associated with the user operation.",
+    "causes": ["Your smart wallet does not have funds to send transaction."],
+    "solutions": [
+      "If you are not using a paymaster, verify that the sender address has enough native tokens to cover the required prefund.",
+      "Send some native tokens in your smart wallet to be able to resolve the error.",
+      "If you are looking to use a paymaster to cover the gas fees, verify that the paymasterAndData field is set."
+    ]
+}
+```
+
 ### [Hosted errors](https://bcnmy.github.io/aa-errors/errors.json)