add examples to doc

Author: anafalcao

docs/core/logger.md

@@ -194,7 +194,17 @@ You can append your own keys to your existing Logger via `append_keys(**addition
 
 The append_context_keys method allows temporary modification of a Logger instance's context without creating a new logger. It's useful for adding context keys to specific workflows while maintaining the logger's overall state and simplicity.
 
-* Add examples
+=== "append_context_keys.py"
+
+    ```python hl_lines="7 8"
+    --8<-- "examples/logger/src/append_context_keys.py"
+    ```
+
+=== "append_context_keys_output.json"
+
+    ```json hl_lines="8 9"
+    --8<-- "examples/logger/src/append_context_keys.json"
+    ```
 
 #### ephemeral metadata
 

examples/logger/src/append_context_keys.json

@@ -0,0 +1,18 @@
+[
+    {
+        "level": "INFO",
+        "location": "lambda_handler:8",
+        "message": "Log with context",
+        "timestamp": "2024-03-21T10:30:00.123Z",
+        "service": "example_service",
+        "user_id": "123",
+        "operation": "process"
+    },
+    {
+        "level": "INFO",
+        "location": "lambda_handler:10",
+        "message": "Log without context",
+        "timestamp": "2024-03-21T10:30:00.124Z",
+        "service": "example_service"
+    }
+]

examples/logger/src/append_context_keys.py

@@ -0,0 +1,13 @@
+from aws_lambda_powertools import Logger
+from aws_lambda_powertools.utilities.typing import LambdaContext
+
+logger = Logger(service="example_service")
+
+
+def lambda_handler(event: dict, context: LambdaContext) -> str:
+    with logger.append_context_keys(user_id="123", operation="process"):
+        logger.info("Log with context")
+
+    logger.info("Log without context")
+
+    return "hello world"