Prosody Appimage: supports only x86_64:

* stop trying to generated an ARM64 AppImage (as it is buggy)
* display a warning in the settings if incompatible CPU detected
* documentation for a workaround

Implements #120.

documentation/installation.ja.md

@@ -16,3 +16,67 @@ v6.0.0から、このプラグインはProsodyのインストールが不要に
 このバージョンより前の環境で本プラグインを既にご使用中で、手動でProsodyをインストールした場合は、Prosodyのアンインストールが可能です。
 
 Prosodyが内蔵されたカスタムDockerイメージをご利用の場合は、公式のPeerTube Dockerイメージに切り替えることができるようになりました。
+
+## Known issues: CPU compatibility
+
+The Prosody AppImage included in the plugin will only work on x86_64 CPU.
+It is not compatible with arm64 and other CPU architectures.
+
+For now, I did not manage to make it work for other CPU architectures.
+If you want te be notified when it will be possible, you can subscribe and comment this
+[issue](https://github.com/JohnXLivingston/peertube-plugin-livechat/issues/124).
+
+To use the plugin, you will have to manually install Prosody on your server
+(see below).
+
+Once it is done, you have to check `Use system Prosody` in the plugin settings.
+
+### On non-docker Peertube installation
+
+For standard installation, you just have to install the official `prosody` package
+for your linux distribution.
+
+For example, on Debian/Ubuntu:
+
+```bash
+sudo apt install prosody
+```
+
+You can then disable the service that starts automatically when you install
+Prosody (the plugin will launch a Prosody process, there is no need for the
+service to run).
+For example, on Debian/Ubuntu (and other Systemd based linux distributions):
+
+```bash
+sudo systemctl disable prosody && sudo systemctl stop prosody
+```
+
+Warning: do not disable Prosody if it is used for another service on your server,
+like for example Jitsi.
+
+### Docker
+
+You will have to generate a Peertube image that includes Prosody in the same
+container that Peertube.
+I know this is not the standard way to do this with Docker, but keep in mind it
+is a temporary workaround.
+
+To generate and use such an image, please refer to the Docker documentation.
+The Docker file to generate the image should be:
+
+```Docker
+FROM chocobozzz/peertube:production-bullseye
+
+RUN apt -y update && apt install -y prosody && apt -y clean
+```
+
+### Yunohost
+
+You have to disable `metronome` (the XMPP server provided by Yunohost), and
+install `prosody`.
+
+This is already done by the Yunohost Peertube application, as it was required for the
+plugin before the v6.0.0.
+But it may be removed in a near feature (to avoid drawbacks of this method).
+I have to discuss with Yunohost team, to decide how we can do to minimize drawbacks,
+and maximize compatibility.