chore(docs): added documentation

Author: rubenfonseca

docs/core/event_handler/api_gateway.md

@@ -272,7 +272,7 @@ When using [Custom Domain API Mappings feature](https://docs.aws.amazon.com/apig
 
 **Scenario**: You have a custom domain `api.mydomain.dev`. Then you set `/payment` API Mapping to forward any payment requests to your Payments API.
 
-**Challenge**: This means your `path` value for any API requests will always contain `/payment/<actual_request>`, leading to HTTP 404 as Event Handler is trying to match what's after `payment/`. This gets further complicated with an [arbitrary level of nesting](https://github.com/aws-powertools/powertools-lambda-roadmap/issues/34){target="_blank"}.
+**Challenge**: This means your `path` value for any API requests will always contain `/payment/<actual_request>`, leading to HTTP 404 as Event Handler is trying to match what's after `payment/`. This gets further complicated with an [arbitrary level of nesting](https://github.com/aws-powertools/powertools-lambda/issues/34){target="_blank"}.
 
 To address this API Gateway behavior, we use `strip_prefixes` parameter to account for these prefixes that are now injected into the path regardless of which type of API Gateway you're using.
 
@@ -293,6 +293,14 @@ To address this API Gateway behavior, we use `strip_prefixes` parameter to accou
 
 	For example, when using `strip_prefixes` value of `/pay`, there is no difference between a request path of `/pay` and `/pay/`; and the path argument would be defined as `/`.
 
+For added flexibility, you can use regexes to strip a prefix. This is helpful when you have many options due to different combinations of prefixes (e.g: multiple environments, multiple versions).
+
+=== "strip_route_prefix_regex.py"
+
+    ```python hl_lines="12"
+    --8<-- "examples/event_handler_rest/src/strip_route_prefix_regex.py"
+    ```
+
 ## Advanced
 
 ### CORS

examples/event_handler_rest/src/strip_route_prefix_regex.py

@@ -0,0 +1,21 @@
+import re
+
+from aws_lambda_powertools.event_handler import APIGatewayRestResolver
+from aws_lambda_powertools.utilities.typing import LambdaContext
+
+# This will support:
+# /v1/dev/subscriptions/<subscription>
+# /v1/stg/subscriptions/<subscription>
+# /v1/qa/subscriptions/<subscription>
+# /v2/dev/subscriptions/<subscription>
+# ...
+app = APIGatewayRestResolver(strip_prefixes=[re.compile(r"/v[1-3]+/(dev|stg|qa)")])
+
+
+@app.get("/subscriptions/<subscription>")
+def get_subscription(subscription):
+    return {"subscription_id": subscription}
+
+
+def lambda_handler(event: dict, context: LambdaContext) -> dict:
+    return app.resolve(event, context)