Website improvements

[cbix]

Continuation of #29:

• reorganize content + templates
• split out package details (or at least file list) to separate pages, otherwise the page will get huge eventually
• rework footer, use current year
• rework package file list to either distinguish files/dirs better or not at all
• allow collapsing the table entries again
• add hint after "Contributions are welcome!": To suggest software for inclusion in the repo open a [Github issue](https://github.com/osam-cologne/archlinux-proaudio/issues).
• Make content wider for higher resolution (>1080 width) screens
• Set title
• set meta fields