doc: add brief intro on using traefik as reverse-proxy (go-gitea#19432)

Author: duskmoon314

docs/content/doc/usage/reverse-proxies.en-us.md

@@ -348,3 +348,18 @@ The added http-request will automatically add a trailing slash if needed and int
 
 Then you **MUST** set something like `[server] ROOT_URL = http://example.com/gitea/` correctly in your configuration.
 
+## Traefik
+
+If you want traefik to serve your Gitea instance, you can add the following label section to your `docker-compose.yaml` (Assuming the provider is docker).
+
+```yaml
+gitea:
+  image: gitea/gitea
+  ...
+  labels:
+    - "traefik.enable=true"
+    - "traefik.http.routers.gitea.rule=Host(`example.com`)"
+    - "traefik.http.services.gitea-websecure.loadbalancer.server.port=3000"
+```
+
+This config assumes that you are handling HTTPS on the traefik side and using HTTP between Gitea and traefik.

docs/content/doc/usage/reverse-proxies.zh-cn.md

@@ -106,3 +106,19 @@ git.example.com {
 ```
 
 然后您**必须**在 Gitea 的配置文件中正确的添加类似 `[server] ROOT_URL = http://git.example.com/git/` 的配置项。
+
+## 使用 Traefik 作为反向代理服务
+
+如果您想使用 traefik 作为 Gitea 的反向代理服务，您可以在 `docker-compose.yaml` 中添加 label 部分（假设使用 docker 作为 traefik 的 provider）：
+
+```yaml
+gitea:
+  image: gitea/gitea
+  ...
+  labels:
+    - "traefik.enable=true"
+    - "traefik.http.routers.gitea.rule=Host(`example.com`)"
+    - "traefik.http.services.gitea-websecure.loadbalancer.server.port=3000"
+```
+
+这份配置假设您使用 traefik 来处理 HTTPS 服务，并在其和 Gitea 之间使用 HTTP 进行通信。