Fediverse: Move Secure Fetch documentation to the 'Usage' section

plugins/Fediverse/plugin.py

@@ -114,7 +114,30 @@ class FediverseHttp(httpserver.SupyHTTPServerCallback):
 
 
 class Fediverse(callbacks.PluginRegexp):
-    """Fetches information from ActivityPub servers."""
+    """Fetches information from ActivityPub servers.
+
+    Enabling Secure Fetch
+    ^^^^^^^^^^^^^^^^^^^^^
+
+    The default configuration works with most ActivityPub servers, but not
+    all of them, because they require an HTTP Signature to fetch profiles
+    and statuses.
+
+    Because of how HTTP Signatures work, you need to add some configuration
+    for Limnoria to support it.
+
+    First, you should set ``supybot.servers.http.port`` to a port you want
+    your bot to listen on (by default it's 8080). If there are already
+    plugins using it (eg. if Fediverse is already running), you should
+    either unload all of them and load them back, or restart your bot.
+
+    Then, you must configure a reverse-proxy in front of your bot (eg. nginx),
+    and it must support HTTPS.
+
+    Finally, set ``supybot.servers.http.publicUrl`` to the public URL of this
+    server (when opening this URL in your browser, it should show a page with
+    a title like "Supybot web server index").
+    """
 
     threaded = True
     regexps = ["usernameSnarfer", "urlSnarfer_"]