vim-node README.md install instructions update

[dmwaff]

https://github.com/moll/vim-node
README.md

Using Wget:
wget https://github.com/moll/vim-node/archive/master.tar.gz -O- | tar -xf- --strip-components 1 -C ~/.vim/bundle/node

1. Requires tar's -z option (tar -x -z -f ) to gunzip the tar.gz file.
2. Readability recommendation only, add space between wget -O option and stdout (-).
3. Readability recommendation only, add space between tar -f option and stdin (-).

Using long options:
wget --output-document=- https://github.com/moll/vim-node/archive/master.tar.gz | tar --extract --gunzip --strip-components 1 --file=- --directory=~/.vim/bundle/node
OR
Using short options:
wget -O - https://github.com/moll/vim-node/archive/master.tar.gz | tar --strip-components 1 -xzf - -C ~/.vim/bundle/node

Cheers