[Manifest Tools] Added step in document to install grunt-cli
[Manifest Tools] Added step in document to install grunt-cli

f2bo/ManifoldJS,f2bo/ManifoldJS-lib,BobJavascript/ManifoldJS,ArchivedRepos/ManifoldJS,NoobsArePeople2/ManifoldJS,maitret/ManifoldJS,f2bo/ManifoldJS,f2bo/ManifoldJS-lib,dragthor/ManifoldJS,AuyaJackie/ManifoldJS,beni55/ManifoldJS,manifoldjs/ManifoldJS