Better installation instructions in the readme

[bmesuere]

The installation instructions in the readme should be a bit longer and also targeted towards non-computer scientists. The recommended way is probably using cargo. The instructions to compile it from source are missing.

[ninewise]

I'd actually recommend the binary installation to non-computer scientists.

I've made some changes in 7b554e5, could you check if this clarifies the instructions? I've split the "from source" instructions in two parts so it's more visible that the crates.io is a source release as well.

[bmesuere]

But binary is not easy to update?

[ninewise]

It is indeed harder to automatically update; I've added update instructions as well now, and marked crates.io as recommended installation method.