Provide .clang-format & .clang-tidy

[marcluque]

This makes the coding style for the project consistent. Could be combined with a simple script or even local commit hook that runs it for all files.

[marcluque]

I could make a proposal for a clang-format file. But I'd wait for #10 to be finished to not run into any struggles with merges.

[marcluque]

Just a quick question for that. Should we use tabs or spaces for indentation? In the latter case, how many?

[marcluque]

I've also noticed that the naming conventions are a bit inconsistent. Is there any specific rule that should be followed? I think that clang-tidy can enforce naming conventions. Just as an example camelCase vs snake_case for variables and struct members.