Reduce info at startpage

[TobiasNx]

[...] I generally think that there is also too much information at https://metafacture.org/ and we should at one point re-work the page to make it easier to grasp what Metafacture is with just reading a few bullet points.

Originally posted by @acka47 in #162

[TobiasNx]

The same text should be used here metafacture/metafacture-core#444