Extend Readme.rd

[Seikilos]

Hello,
the installation guide is quite thin and took me sometime to figure out the missing parts.

First you should mention that the location in vendor should be
Xlab/pChartBundle.

Following deps file worked for me

[pChartBundle]
    git=https://github.com/rbakels/pChartBundle
    target=/Xlab/pChartBundle

Beside the AppKernel I also had to extend the autoload.php by adding the line:

'Xlab'             => __DIR__.'/../vendor',

If it worked for you without these steps. Please hint me what you have done

[rbakels]

Sorry for the late response. I will try to fix the README (or extend the README). Thanks.