0008-community-plugins.md needs discuss

@z8674558

Yes, I think it's important to support and promote community plug-ins.

EMQ encourages the community to contribute useful plug-ins. If we do it well enough, we can help the author promote it.

0008 is a little simple and inflexible

1. How to approve new plug-ins for the released EMQ X version
2. The security of the plug-in, whether the plug-in is officially recommended by EMQ, and whether it infringes the copyright or interests of some people
3. The version compatibility of the plug-in, users may ask: this plug-in is cool, but can I use it in my EMQ X?

[Grafana sign-a-plugin](https://grafana.com/docs/grafana/latest/developers/plugins/sign-a-plugin/
)
[Grafama plugins](https://grafana.com/grafana/plugins/)

**We can build an online plug-in market, which has been discussed before, but we have encountered some technical problems.**

If we can solve the problem now, the plug-in market looks very cool

1. Can we provide a `*.zip` file (plugin installation package, like `emqx_auth_sqlite_plugins.zip`), which contains the main `*.beam` file. The user can set it to the `lib/` directory, unzip it, and reload it?

### Usage

```bash
wget https://market.emqx.io/plugins/emqx/emqx_auth_sqlite.zip?version=1.3.1
unzip emqx_auth_sqlite.zip
mv emqx_auth_sqlite/ /opt/emqx/lib/

emqx_ctl plugins load emqx_auth_sqlite
```