added grain docs to env functions

Signed-off-by: Matt Butcher <matt.butcher@microsoft.com>

Author: technosophos

env.gr

@@ -5,6 +5,8 @@ import String from "string"
 import Option from "option"
 
 // Split an environment variable at the first equals sign.
+// @param item: An environment variable pair, separated by an equals sign (=).
+// @return (String, String) A tuple key/value pair.
 let splitEnvVar = (item) => {
     let offsetOpt = String.indexOf("=", item)
 
@@ -16,6 +18,9 @@ let splitEnvVar = (item) => {
     (key, val)
 }
 
+// Get the environment variables as a Map<String, String>
+//
+// @return Map<String, String> A map of all environment variables.
 export let envMap = () =>  {
     let parsed = Map.make()
     let env = Process.env()