Add jemalloc install instruction for mac (#9879)

### What problem does this PR solve?

Add jemalloc install instruction for mac

### Type of change

- [x] Documentation Update

README.md

@@ -348,6 +348,8 @@ docker build --platform linux/amd64 -f Dockerfile -t infiniflow/ragflow:nightly
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
    
 6. Launch backend service:

README_id.md

@@ -312,6 +312,8 @@ docker build --platform linux/amd64 -f Dockerfile -t infiniflow/ragflow:nightly
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
 
 6. Jalankan aplikasi backend:

README_ja.md

@@ -307,6 +307,8 @@ docker build --platform linux/amd64 -f Dockerfile -t infiniflow/ragflow:nightly
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
 
 6. バックエンドサービスを起動する:

README_ko.md

@@ -306,6 +306,8 @@ docker build --platform linux/amd64 -f Dockerfile -t infiniflow/ragflow:nightly
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
 
 6. 백엔드 서비스를 시작합니다:

README_pt_br.md

@@ -330,6 +330,8 @@ docker build --platform linux/amd64 -f Dockerfile -t infiniflow/ragflow:nightly
     sudo apt-get install libjemalloc-dev
     # centos
     sudo yum instalar jemalloc
+    # mac
+    sudo brew install jemalloc
     ```
 
 6. Lance o serviço de back-end:

README_tzh.md

@@ -343,6 +343,8 @@ docker build --platform linux/amd64 --build-arg NEED_MIRROR=1 -f Dockerfile -t i
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
 
 6. 啟動後端服務：

README_zh.md

@@ -342,6 +342,8 @@ docker build --platform linux/amd64 --build-arg NEED_MIRROR=1 -f Dockerfile -t i
    sudo apt-get install libjemalloc-dev
    # centos
    sudo yum install jemalloc
+   # mac
+   sudo brew install jemalloc
    ```
 
 6. 启动后端服务：