Changed the documentation to specify v before 'version' and code changes to append 'v' if it not provided in version (#11) (#15)

* Chnaged the documentation to sepcify v before 'version'

* append v to version incase it does not already include

* review comments fix

lib/run.js

@@ -130,6 +130,9 @@ function run() {
         if (version.toLocaleLowerCase() === 'latest') {
             version = yield getStableHelmVersion();
         }
+        else if (!version.toLocaleLowerCase().startsWith('v')) {
+            version = 'v' + version;
+        }
         let cachedPath = yield downloadHelm(version);
         try {
             if (!process.env['PATH'].startsWith(path.dirname(cachedPath))) {