Add a News feed

We have relevant information about CloudNativePG that we never reflect in the website.
I think it would be cool to have a Twitter-like feed of short snippets with links.
Many of these things cannot/should not have a dedicated blog article in the CNPG website.

Example of news snippets:
- Links to talks given at Kubecon or other venues
- New tutorials published by Gabriele in his personal site
- Links to articles or videos with operator comparisons etc.
- Upcoming things, e.g. presence at Kubecon

The issue names no files, tests, or entry points. Start by locating the website's existing blog or content structure, then define the feed's content model, publishing workflow, and display location; done means short linked news items can be added and shown consistently.

由索引模型根據 Issue 內容生成。