Fix broken logo in README and worng header style.
Fix broken logo in README and worng header style.

I changed `JVlogo.png` (this file never existed) to `https://javers.org/img/logotype.svg`.
Added missing space between `#` and a header to properly style header.
Removed spaces at the end of the line.

javers/javers.github.io,javers/javers.github.io,javers/javers.github.io,javers/javers.github.io