Add project statistics and convert to sortable table

As part of a university project, we wrote [a report](https://github.com/rjagerman/ANON) about the current state of (decentralized) privacy enhancing networks. As part of this report we used the data from this repository and combined this with data from [Ohloh](https://www.ohloh.net) to give us more insight into the state of these projects.

Our supervisor emailed with Ross Jones and he was very positive about contributing this back into the current project index.


The technical details:

This pull request changes the previous alternative internet project index into a sortable table with project statistics sourced from ohloh.net.

To achieve this, every project currently in the README.md was converted to a JSON file, found in projects/. Pull requests for new projects should be done by adding a new JSON file in the projects/ folder and using the included update.py to regenerate the README.md files.

For more info, see the included CONTRIBUTING.md.