update readme

Author: Joe Snell

README.md

@@ -13,11 +13,11 @@ To get started you can use the default `Extension` class, or extend it.
 Example:
 
 ```python
-from lef import Extension
+import lef
 
 def handler(event):
     print(event)
 
-extension = Extension()
-extension.register([EventType.INVOKE], handler)
+extension = lef.Extension()
+extension.register([lef.EventType.INVOKE], handler)
 ```

pyproject.toml

@@ -13,7 +13,7 @@ keywords = [
     "AWS Lambda",
     "Lambda Extensions",
     "Framework",
-    "Extension Framework"
+    "Lambda Extension Framework"
 ]
 
 packages = [