docs: Mark the async SSE client as experimental

Author: jsonbailey

README.md

@@ -22,6 +22,11 @@ An async implementation, `AsyncSSEClient`, is also available for use with `async
 pip install launchdarkly-eventsource[async]
 ```
 
+> [!CAUTION]
+> The async implementation (`AsyncSSEClient` and its associated `AsyncConnectStrategy` API) is experimental and should NOT be considered ready for production use. It may change or be removed without notice and is not subject to backwards compatibility guarantees.
+>
+> Pin to a specific minor version and review the changelog before upgrading.
+
 ## Supported Python versions
 
 This version of the package is compatible with Python 3.9 and higher.

ld_eventsource/async_client.py

@@ -16,6 +16,11 @@ class AsyncSSEClient:
     """
     An async client for reading a Server-Sent Events stream.
 
+    CAUTION:
+        This feature is experimental and should NOT be considered ready for production use.
+        It may change or be removed without notice and is not subject to backwards
+        compatibility guarantees.
+
     This is an async/await implementation. The expected usage is to create an ``AsyncSSEClient``
     instance (either as an async context manager or directly), then read from it using the async
     iterator properties :attr:`events` or :attr:`all`.

ld_eventsource/config/async_connect_strategy.py

@@ -10,6 +10,11 @@ class AsyncConnectStrategy:
     """
     An abstraction for how :class:`.AsyncSSEClient` should obtain an input stream.
 
+    CAUTION:
+        This feature is experimental and should NOT be considered ready for production use.
+        It may change or be removed without notice and is not subject to backwards
+        compatibility guarantees.
+
     The default implementation is :meth:`http()`, which makes HTTP requests with ``aiohttp``.
     Or, if you want to consume an input stream from some other source, you can create your own
     subclass of :class:`AsyncConnectStrategy`.
@@ -58,6 +63,11 @@ class AsyncConnectionClient:
     """
     An object provided by :class:`.AsyncConnectStrategy` that is retained by a single
     :class:`.AsyncSSEClient` to perform all connection attempts by that instance.
+
+    CAUTION:
+        This feature is experimental and should NOT be considered ready for production use.
+        It may change or be removed without notice and is not subject to backwards
+        compatibility guarantees.
     """
 
     async def connect(self, last_event_id: Optional[str]) -> AsyncConnectionResult:
@@ -85,6 +95,11 @@ async def __aexit__(self, type, value, traceback):
 class AsyncConnectionResult:
     """
     The return type of :meth:`AsyncConnectionClient.connect()`.
+
+    CAUTION:
+        This feature is experimental and should NOT be considered ready for production use.
+        It may change or be removed without notice and is not subject to backwards
+        compatibility guarantees.
     """
 
     def __init__(