Making the pymt installation instructions more foolproof

[gregtucker]

Based on an impromptu usability test, the pymt installation instructions are written in a way that leads users to the "advanced" install rather than the "quick start". This is because the item "Installation" jumps out to the eye more than "Install pymt" under "Quick start". Potential solutions could be:

1. put a link to the Quick Start version as the first item under "Installation", so maybe 3 items: Quick start installation; Advanced: Stable Release; Advanced: From Source

2. Rename the "Installation" to something like "Advanced Installation"