improve documentation about F7-React and "react-router"

[nimo23]

According to https://forum.framework7.io/t/framework7-react-routes/10097, https://reactrouter.com does not work out of the box in combination with "framework7-react"-components. So the only solution would be to stick with F7-router.

Would be nice to include this limitation into official "F7 routing documentation", because I wanted to include react-router and it is not obvious that this is not compatible with "F7-React" even if the f7-react-components itself are decoupled from the routing logic.