* Reduce the version of `bearssl` to 0.0.2 to increment minimally from
the existing crate.
* Add an overview README for a high level description.
* Add crate tags and categories for easier discoverability in the
future.
* The `bearssl-sys` crate is basically usable at this point.
* The `bearssl` crate itself needs a lot work before being usable. The
design needs heavy iterations, considerationg and love.
Aydin Mercan