docs(examples): add type hints to things WSGI/ASGI samples (#2698)

* docs(examples): add type hints to things WSGI/ASGI samples

Annotate on_get request/response parameters in the tutorial examples
as a small first slice of #1820. No runtime behavior change.

Signed-off-by: Alex Chen <l46983284@gmail.com>

* docs(examples): type ASGI things handlers with falcon.asgi types

Use falcon.asgi.Request/Response in the ASGI sample so the annotations
match the ASGI app surface, not the WSGI base classes.

Signed-off-by: Alex Chen <l46983284@gmail.com>

* docs(examples): drop future annotations; sync README snippets

Remove unnecessary from __future__ import annotations from the short
things samples and mirror the typed responder signatures (plus ASGI
Request/Response imports) in the inline README.rst copies.

Signed-off-by: Alex Chen <l46983284@gmail.com>

Author: l46983284-cpu

README.rst

@@ -344,7 +344,7 @@ WSGI app (the ASGI version is included further down):
     # other things) that you think in terms of resources and state
     # transitions, which map to HTTP verbs.
     class ThingsResource:
-        def on_get(self, req, resp):
+        def on_get(self, req: falcon.Request, resp: falcon.Response) -> None:
             """Handles GET requests"""
             resp.status = falcon.HTTP_200  # This is the default status
             resp.content_type = falcon.MEDIA_TEXT  # Default is JSON, so override
@@ -392,13 +392,15 @@ The ASGI version of the example is similar:
 
     import falcon
     import falcon.asgi
+    from falcon.asgi import Request
+    from falcon.asgi import Response
 
 
     # Falcon follows the REST architectural style, meaning (among
     # other things) that you think in terms of resources and state
     # transitions, which map to HTTP verbs.
     class ThingsResource:
-        async def on_get(self, req, resp):
+        async def on_get(self, req: Request, resp: Response) -> None:
             """Handles GET requests"""
             resp.status = falcon.HTTP_200  # This is the default status
             resp.content_type = falcon.MEDIA_TEXT  # Default is JSON, so override

examples/things.py

@@ -10,7 +10,7 @@
 # other things) that you think in terms of resources and state
 # transitions, which map to HTTP verbs.
 class ThingsResource:
-    def on_get(self, req, resp):
+    def on_get(self, req: falcon.Request, resp: falcon.Response) -> None:
         """Handles GET requests"""
         resp.status = falcon.HTTP_200  # This is the default status
         resp.content_type = falcon.MEDIA_TEXT  # Default is JSON, so override

examples/things_asgi.py

@@ -2,13 +2,15 @@
 
 import falcon
 import falcon.asgi
+from falcon.asgi import Request
+from falcon.asgi import Response
 
 
 # Falcon follows the REST architectural style, meaning (among
 # other things) that you think in terms of resources and state
 # transitions, which map to HTTP verbs.
 class ThingsResource:
-    async def on_get(self, req, resp):
+    async def on_get(self, req: Request, resp: Response) -> None:
         """Handles GET requests"""
         resp.status = falcon.HTTP_200  # This is the default status
         resp.content_type = falcon.MEDIA_TEXT  # Default is JSON, so override