TLS documentation: Apply suggestions

Signed-off-by: Julien Pivotto <[email protected]>

README.md

@@ -596,14 +596,15 @@ offending pusher.
 ## TLS and basic authentication
 
 The Pushgateway supports TLS and basic authentication. This enables better
-control of the API's.
+control of the various HTTP endpoints.
 
 To use TLS and/or basic authentication, you need to pass a configuration file
 using the `--web.config.file` parameter. The format of the file is described
 [in the exporter-toolkit repository](https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md).
 
-Note that the TLS and basic authentication settings affects the API's to
-push metrics, the /metrics endpoint used by Prometheus and the web UI.
+Note that the TLS and basic authentication settings affect all HTTP endpoints:
+/metrics for scraping, the API to push metrics via /metrics/..., the admin API
+via /api/..., and the web UI.
 
 ## Development