Add build example to README.md

README.md

@@ -8,7 +8,9 @@ Prometheus exporter with plugable metric collectors.
 
 By default it will only include the NativeCollector.
 
-To include other collectors, specify the build tags accordently.
+To include other collectors, specify the build tags lile this:
+
+    go build -tags 'ganglia runit' node_exporter.go
 
 
 ### NativeCollector
@@ -19,12 +21,12 @@ read from `node_exporter.conf`.
 To disable the native collector, use build tag `nonative`.
 
 
-### GmondCollector
+### GmondCollector (tag: ganglia)
 
 Talks to a local gmond and provide it's metrics.
 
 
-### RunitCollector
+### RunitCollector (tag: runit)
 
 Provides metrics for each runit services like state and how long it
 has been in that state.