Add basic auth and reloading to configuration docs

content/docs/operating/configuration.md

@@ -14,6 +14,11 @@ load](/docs/querying/rules/#configuring-rules).
 
 To view all available command-line flags, run `prometheus -h`.
 
+Prometheus can reload its configuration at runtime. If the new configuration
+is not well-formatted the changes will not be applied.
+A configuration reload is triggered by sending `SIGHUP` to the Prometheus process.
+This will also reload any configured rule files.
+
 
 ## Configuration file
 
@@ -93,6 +98,11 @@ job_name: <name>
 # The URL scheme with which to fetch metrics from targets.
 [ scheme: <scheme> | default = http ] 
 
+# HTTP basic authentication information.
+basic_auth:
+  [ username: <string> ]
+  [ password: <string> ]
+
 # List of DNS service discovery configurations.
 dns_sd_configs:
   [ - <dns_sd_config> ... ]

content/docs/querying/rules.md

@@ -10,7 +10,10 @@ Prometheus supports two types of rules which may be configured and then
 evaluated at regular intervals: recording rules and alerting rules. To include
 rules in Prometheus, create a file containing the necessary rule statements and
 have Prometheus load the file via the `rule_files` field in the [Prometheus
-configuration](https://github.com/prometheus/prometheus/blob/master/config/config.proto).
+configuration](/docs/operating/configuration).
+
+The rule files can be reloaded at runtime by sending `SIGHUP` to the Prometheus
+process. The changes are only applied if all rule files are well-formatted.
 
 ## Syntax-checking rules
 To quickly check whether a rule file is syntactically correct without starting