Add documentation for changing SITE param in perforce configuration.

api/integrations/perforce/zulip_perforce_config.py

@@ -24,6 +24,7 @@
 # Change these values to configure authentication for the plugin
 ZULIP_USER = "p4-bot@example.com"
 ZULIP_API_KEY = "0123456789abcdef0123456789abcdef"
+ZULIP_SITE = "https://zulip.example.com"
 
 # commit_notice_destination() lets you customize where commit notices
 # are sent to with the full power of a Python function.
@@ -57,6 +58,3 @@ def commit_notice_destination(path, changelist):
 ## If properly installed, the Zulip API should be in your import
 ## path, but if not, set a custom path below
 ZULIP_API_PATH = None
-
-# This should not need to change unless you have a custom Zulip subdomain.
-ZULIP_SITE = "https://api.zulip.com"

templates/zerver/integrations.html

@@ -1473,10 +1473,12 @@ key = NAGIOS_BOT_API_KEY
         <code>/usr/local/share/zulip/integrations/perforce</code></li>
 
         <li>Open <code>integrations/perforce/zulip_perforce_config.py</code> in
-        your favorite editor and change the <code>ZULIP_USER</code> and
+        your favorite editor, change the <code>ZULIP_USER</code> and
         <code>ZULIP_API_KEY</code> variables at the top of the file to the
         credentials for the bot you'd like to use for this integration.</li>
 
+        <li>You should also change <code>ZULIP_SITE</code> to {{ external_api_path_subdomain }}</li>
+
         <li>Edit your
         <a href="http://www.perforce.com/perforce/doc.current/manuals/p4sag/chapter.scripting.html#d0e14583">trigger table</a>
         with <code>p4 triggers</code> and add an entry something like the