fix(docs): fix pd.peers conf loss in quick_start.md (#453)

Author: Tsukilc

content/cn/docs/quickstart/hugegraph/hugegraph-server.md

@@ -222,6 +222,8 @@ pd.peers=127.0.0.1:8686
 
 ```properties
 usePD=true
+# 注意，1.7.0 必须在 rest-server.properties 配置 pd.peers
+pd.peers=127.0.0.1:8686,127.0.0.1:8687,127.0.0.1:8688
 
 # 若需要 auth 
 # auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator

content/en/docs/quickstart/hugegraph/hugegraph-server.md

@@ -239,6 +239,8 @@ Then enable PD discovery in `rest-server.properties` (required for every HugeGra
 ```properties
 usePD=true
 
+# notice: must have this conf in 1.7.0
+pd.peers=127.0.0.1:8686,127.0.0.1:8687,127.0.0.1:8688
 # If auth is needed
 # auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator
 ```