Default to allow the server to create >= 100 uni and >=100 bidi streams.

index.bs

@@ -1342,13 +1342,17 @@ that determine how the [=WebTransport session=] is established and used.
 : <dfn for="WebTransportOptions" dict-member>anticipatedConcurrentIncomingUnidirectionalStreams</dfn>
 :: Optionally lets an application specify the number of concurrently open
    [=incoming unidirectional=] streams it anticipates the server creating.
+   If null, the user agent MUST from the outset allow at least 100 [=incoming unidirectional=]
+   streams from the server.
    If not null, the user agent SHOULD attempt to reduce round-trips by taking
    {{[[AnticipatedConcurrentIncomingUnidirectionalStreams]]}} into consideration in its
    negotiations with the server.
 
 : <dfn for="WebTransportOptions" dict-member>anticipatedConcurrentIncomingBidirectionalStreams</dfn>
 :: Optionally lets an application specify the number of concurrently open
    [=bidirectional=] streams it anticipates a server creating.
+   If null, the user agent MUST from the outset allow the server to create at least 100
+   [=bidirectional=] streams.
    If not null, the user agent SHOULD attempt to reduce round-trips by taking
    {{[[AnticipatedConcurrentIncomingBidirectionalStreams]]}} into consideration in its
    negotiations with the server.