Improve the Home Page

The home page hasn't had any changes done since the beginning of CloudNativePG.
There are many relevant pieces of info that we could be reflecting here.
E.g. Volume snapshots. Kubecon talks. OpenShift certification

The content we do have there is spread out and somewhat generic.
Maybe we should have a compact table with a feature listing, which could start in the first screenful.

從網站首頁開始，檢視目前的內容如何分布在首屏中。盤點 issue 中提到的相關資訊，包括 volume snapshots、KubeCon 演講、OpenShift certification，以及現有的 feature content。完成的標準是頁面呈現精簡、清楚的 feature 清單，以及更加聚焦的目前資訊。

由索引模型根據 Issue 內容生成。