Documentation: Install node.js from website

[jeff1evesque]

We need to update the Pre-Installation subsection to reflect that we will be acquiring node.js from the web, instead of the Ubuntu Package Center (apt-get), https://github.com/jeff1evesque/grunt/issues/7#issuecomment-48002262.

So, we will change the following:

# Sass (ruby)
sudo apt-get install rubygems1.8
sudo apt-get install libhaml-ruby1.8
sudo gem install sass

# node.js
sudo apt-get install nodejs

# npm
sudo apt-get install mricron

to the following:

# Sass (ruby)
sudo apt-get install rubygems1.8
sudo apt-get install libhaml-ruby1.8
sudo gem install sass

# node.js, 10.28 - Ubuntu 14.04+
sudo apt-get install nodejs

# node.js, 10.23 - Ubuntu 13.04-
$ sudo wget http://nodejs.org/dist/v0.10.23/node-v0.10.23.tar.gz -O - | tar -xz
$ cd node-v0.10.23
$ ./configure
$ sudo make install
$ cd ..
$ sudo rm -R node-v0.10.23

[jeff1evesque]

Minor, remove extra newline.