Document how to turn off Piwik and bug reports (element-hq#6738)

README.md

@@ -134,7 +134,8 @@ For a good example, see https://riot.im/develop/config.json
 1. `integrations_rest_url`: URL to the REST interface for the integrations server.
 1. `integrations_widgets_urls`: list of URLs to the REST interface for the widget integrations server.
 1. `bug_report_endpoint_url`: endpoint to send bug reports to (must be running a
-   https://github.com/matrix-org/rageshake server)
+   https://github.com/matrix-org/rageshake server). Bug reports can be disabled by leaving the 
+   `bug_report_endpoint_url` out of your config file.
 1. `roomDirectory`: config for the public room directory. This section is optional.
 1. `roomDirectory.servers`: List of other homeservers' directories to include in the drop
    down list. Optional.
@@ -147,11 +148,11 @@ For a good example, see https://riot.im/develop/config.json
    anything else since it is used to isolate the privileges of file attachments to this
    domain. Default: `https://usercontent.riot.im/v1.html`. This needs to contain v1.html from
    https://github.com/matrix-org/usercontent/blob/master/v1.html
-1. `piwik`: an object containing the following properties:
-    1. `url`: The URL of the Piwik instance to use for collecting Analytics
-    1. `whitelistedHSUrls`: a list of HS URLs to not redact from the Analytics
-    1. `whitelistedISUrls`: a list of IS URLs to not redact from the Analytics
-    1. `siteId`: The Piwik Site ID to use when sending Analytics to the Piwik server configured above
+1. `piwik`: Analytics can be disabled by setting `piwik: false` or by leaving the piwik config option out of your config file. If you want to enable analytics, set `piwik` to be an object containing the following properties:
+    1. `url`: The URL of the Piwik instance to use for collecting analytics
+    1. `whitelistedHSUrls`: a list of HS URLs to not redact from the analytics
+    1. `whitelistedISUrls`: a list of IS URLs to not redact from the analytics
+    1. `siteId`: The Piwik Site ID to use when sending analytics to the Piwik server configured above
 1. `teamServerConfig`, `teamTokenMap`, `referralBaseUrl`: an obsolete precursor to communities
    with referral tracking; please ignore it.
 1. `welcomeUserId`: the user ID of a bot to invite whenever users register that can give them a tour