Revert: revert changes to contribute.ngdoc

Reverts d9d20e6 and febda8f which sneaked in by accident

docs/content/misc/contribute.ngdoc

@@ -55,16 +55,13 @@ minified AngularJS files:
 # Clone your Github repository:
 git clone "git@github.com:<github username>/angular.js.git"
 
-**Note:** You may need to use sudo (for OSX, *nix, BSD etc) or run your command shell as Administrator (for Windows) to install Grunt &amp;
-Bower globally.
-
 # Go to the AngularJS directory:
 cd angular.js
 
 # Add the main AngularJS repository as an upstream remote to your repository:
 git remote add upstream "https://github.com/angular/angular.js.git"
 
-# Install node.js dependencies(Note: Please check for the stable version of node before installing the essential packages):
+# Install node.js dependencies:
 npm install
 
 # Install bower components: