Added support for setting page location for render in bundle.txt

[programcsharp]

I realized there was no way to set page location in bundle.txt. I wanted to create a modernizr bundle that was rendered in head, so I added support for a [bundle] section with a pageLocation setting.

I switched that parsing regex to a static readonly compiled regex while I was at it.

Also added to docs.

[programcsharp]

Any chance of getting this merged in?