Fix BaseAddress semantics (#45)

README.md

@@ -210,14 +210,12 @@ RestEase is complex, and handles a lot of different stuff.
 * Deserialisation follows the same logic as the `JsonParse` generator,
   and it generally assumes you're using types which `JsonParse` is applied to.
 * Headers are not yet supported.
-* You have to specify the `BaseAddress` on the input client yourself, and you can't have the same client talking to a
-  different `BaseAddress` this way unless you manually set it before making any different request.
-* I haven't yet worked out how to integrate this with a mocked HTTP client; you can always mock up an `HttpClient`,
-  but I prefer to use a mock which defines a single member `SendAsync`.
 * Anonymous parameters are currently forbidden.
+
+There are also some design decisions:
+
 * Every function must take an optional `CancellationToken` (which is good practice anyway);
   so arguments are forced to be tupled.
-  This is a won't-fix for as long as F# requires tupled arguments if any of the args are optional.
 
 # Detailed examples