[mercure] Update docs for v0.11

Author: dunglas

mercure.rst

@@ -68,11 +68,17 @@ clients.
 An official and open source (AGPL) implementation of a Hub can be downloaded
 as a static binary from `Mercure.rocks`_.
 
-Run the following command to start it:
+On Linux and Mac, run the following command to start it:
 
 .. code-block:: terminal
 
-    $ ./mercure --jwt-key='!ChangeMe!' --addr='localhost:3000' --allow-anonymous --cors-allowed-origins='*'
+    SERVER_NAME=:3000 MERCURE_PUBLISHER_JWT_KEY="!ChangeMe!" MERCURE_SUBSCRIBER_JWT_KEY="!ChangeMe!" ./mercure run -config Caddyfile.dev
+
+On Windows run:
+
+.. code-block:: terminal
+
+    $envSERVER_NAME=':3000'; $env:MERCURE_PUBLISHER_JWT_KEY='!ChangeMe!'; $env:MERCURE_SUBSCRIBER_JWT_KEY='!ChangeMe!'; .\mercure.exe run -config Caddyfile.dev
 
 .. note::
 
@@ -175,8 +181,8 @@ the **topic** being updated. This topic should be an `IRI`_
 of the resource being dispatched.
 
 Usually, this parameter contains the original URL of the resource
-transmitted to the client, but it can be any valid `IRI`_, it doesn't
-have to be a URL that exists (similarly to XML namespaces).
+transmitted to the client, but it can be any string or `IRI`_,
+and it doesn't have to be a URL that exists (similarly to XML namespaces).
 
 The second parameter of the constructor is the content of the update.
 It can be anything, stored in any format.