Release planning for the new implementation

[Luthaf]

I finished rewriting most of the code using a WASM build of chemfiles instead of asm.js or node C++ plugins. While the code is fully usable and tested, there are a few the remaining items before we can make an official announcement:

• Write documentation regarding installation & tutorial(the usual examples)
• Switch linting to eslint, since tslint is depreciated
• Finish writting the README, including all badges & browser usage example (potentially with an HTML file reading a file and displaying basic information on it?)

And the hard remaining item

• Figure out how to deal with emscripten FS interface inside a web browser. Ideally, we should provide an open free function taking a File and returning a chemfiles.Trajectory for reading. For writing/appending, we can use emscripten MEMFS, but then we should provide a way for javascript code to download the resulting file. If you have ideas on how to do that, I would like to hear them!

[Luthaf]

• Figure out why the Karma tests are so flaky and what can be done to improve on this. Tests fails with a timeout ~30% of the time