docs: fixed broken link

Author: ethanneff

CONTRIBUTING.md

@@ -12,7 +12,7 @@
 
 ## Data Flow
 
-- Users sets values https://github.com/BranchMetrics/cordova-ionic-phonegap-branch-deep-linking/blob/master/testbed/config.xml#L7-L13
+- Users sets values https://github.com/BranchMetrics/cordova-ionic-phonegap-branch-deep-linking/blob/master/testbed/config.template.xml#L6-L13
 - Hooks run on build https://github.com/BranchMetrics/cordova-ionic-phonegap-branch-deep-linking/blob/master/plugin.xml#L45-L47
 - Hooks call scripts https://github.com/BranchMetrics/cordova-ionic-phonegap-branch-deep-linking/tree/master/src/scripts/hooks
 - Scripts for iOS https://github.com/BranchMetrics/cordova-ionic-phonegap-branch-deep-linking/tree/master/src/scripts/ios