Yiliu/react js homepage 15/trial 2

Created by: flora8984461

This is based on https://github.com/EclipseFdn/events.eclipse.org/pull/87, improve the way to show read more in Event card

Just used display: flex and flex-wrap: wrap , no need to use 2-maps or match-height now, and also need to set auto height for event details.

• (Enhancement) Use match height or try flex when event details is show instead of map twice