Add some advocacy information

[glasserc]

@n1k0 collected the following feedback from Sudweb:

<NiKo`> the person told me that once you're "decided" to learn about kinto it does the job
<NiKo`> he conceded that the main issue was probably to actually make peoiple wanting to learn about it in the first place :)

Maybe we can add some more advocacy information: Kinto is great at X, Y, and Z, or you should use it because A, B, and C.