Improved readme

This is probably the worst way of starting out in a project but I happened to come across it. While I was trying to install, I faced some bumps here and there. So, I added the changes you see on the files for newcomers. They are very small but I hope merging them won't be an issue.

Along with I couldn't help notice that `node_modules` is included in the project directory and not added in `.gitignore`. The folder is not needed because users can install dependencies themselves as they are provided in `package.json`.

The actual process for the installation should be -
 1. installation of `node.js`, `nvm`, `npm`, `coffee-script`
 2. all dependencies should go in `package.json` # that is the purpose of the file
 3. `npm install`

Notes:
 * `nvm` is needed because v0.6.10 is needed for running simplecv-js
 * Ideally all files under `node_modules` should be deleted as they increase the size of the repository and these files are supposed to installed by the user when he sets up the repository. Maybe, to improve the process, a shell script can be provided.