message: add the logo
diff: *A generic framework for on-demand, incrementalized computation.*
  +<img alt="Salsa Logo" src="https://raw.githubusercontent.com/salsa-rs/logo/main/FerrisSalsa4-01.svg" width="200" />
  +
  ## Obligatory warning
  Very much a WORK IN PROGRESS at this point. Ready for experimental use
  