docs: add X-Dragonfly-Use-P2P header for config (#149)

Signed-off-by: Gaius <[email protected]>

docs/reference/configuration/client/dfdaemon.md

@@ -128,6 +128,9 @@ proxy:
   # http://example.com/xyz?Expires=e1&Signature=s1&ns=docker.io and http://example.com/xyz?Expires=e2&Signature=s2&ns=docker.io
   # will generate the same task id.
   # Default value includes the filtered query params of s3, gcs, oss, obs, cos.
+  # `X-Dragonfly-Use-P2P` header can instead of the regular expression of the rule. If the value is "true",
+  # the request will use P2P technology to distribute the content. If the value is "false",
+  # but url matches the regular expression in rules. The request will also use P2P technology to distribute the content.
   rules:
     - regex: 'blobs/sha256.*'
       # useTLS: false

i18n/zh/docusaurus-plugin-content-docs/current/reference/configuration/client/dfdaemon.md

@@ -125,6 +125,8 @@ proxy:
   # http://example.com/xyz?Expires=e1&Signature=s1&ns=docker.io 和 http://example.com/xyz?Expires=e2&Signature=s2&ns=docker.io
   # 将生成相同的任务 ID.
   # 默认值包括过滤后的s3、gcs、oss、obs、cos的查询参数。
+  # `X-Dragonfly-Use-P2P` 可以代替 rules 中的正则匹配，如果值为 `true`，则直接使用 P2P 下载资源。如果值为 `false`，但
+  # rules 中的正则匹配成功，则仍然使用 P2P 下载资源。
   rules:
     - regex: 'blobs/sha256.*'
       # useTLS: false