Allow configuring the maximum ratelimit timeout before erroring

This is useful for cases where a rate limit is known to be
extraordinarily high, but you still want to handle the error.
This is common with routes such as emoji creation.

discord/client.py

@@ -260,6 +260,14 @@ class Client:
         This allows you to check requests the library is using. For more information, check the
         `aiohttp documentation <https://docs.aiohttp.org/en/stable/client_advanced.html#client-tracing>`_.
 
+        .. versionadded:: 2.0
+    max_ratelimit_timeout: Optional[:class:`float`]
+        The maximum number of seconds to wait when a non-global rate limit is encountered.
+        If a request requires sleeping for more than the seconds passed in, then
+        :exc:`~discord.RateLimited` will be raised. By default, there is no timeout limit.
+        In order to prevent misuse and unnecessary bans, the minimum value this can be
+        set to is ``30.0`` seconds.
+
         .. versionadded:: 2.0
 
     Attributes
@@ -280,12 +288,14 @@ class Client:
         proxy_auth: Optional[aiohttp.BasicAuth] = options.pop('proxy_auth', None)
         unsync_clock: bool = options.pop('assume_unsync_clock', True)
         http_trace: Optional[aiohttp.TraceConfig] = options.pop('http_trace', None)
+        max_ratelimit_timeout: Optional[float] = options.pop('max_ratelimit_timeout', None)
         self.http: HTTPClient = HTTPClient(
             self.loop,
             proxy=proxy,
             proxy_auth=proxy_auth,
             unsync_clock=unsync_clock,
             http_trace=http_trace,
+            max_ratelimit_timeout=max_ratelimit_timeout,
         )
 
         self._handlers: Dict[str, Callable[..., None]] = {