Add version flag to documentation

README.md

@@ -8,15 +8,17 @@ Help on flags:
 
 ```
   -insecure
-    	Ignore server certificate if using https (default false)
+    	Ignore server certificate if using https. (default false)
   -log.level value
     	Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal, panic]. (default info)
   -scrape_uri string
-    	URI to apache stub status page (default "http://localhost/server-status/?auto")
+    	URI to apache stub status page. (default "http://localhost/server-status/?auto")
   -telemetry.address string
     	Address on which to expose metrics. (default ":9117")
   -telemetry.endpoint string
     	Path under which to expose metrics. (default "/metrics")
+  -version
+    	Version of the Apache exporter.
 ```
 
 Tested on Apache 2.2 and Apache 2.4.