feat: add shell of startup install mage.

bootstrap_install_mage.bat

@@ -0,0 +1,31 @@
+@echo off
+SETLOCAL
+
+mage -version >nul 2>&1
+IF %ERRORLEVEL% EQU 0 (
+    echo Mage is already installed.
+    GOTO DOWNLOAD
+)
+
+go version >nul 2>&1
+IF NOT %ERRORLEVEL% EQU 0 (
+    echo Go is not installed. Please install Go and try again.
+    exit /b 1
+)
+
+echo Installing Mage...
+go install github.com/magefile/mage@latest
+
+mage -version >nul 2>&1
+IF NOT %ERRORLEVEL% EQU 0 (
+    echo Mage installation failed.
+    echo Please ensure that %GOPATH%/bin is in your PATH.
+    exit /b 1
+)
+
+echo Mage installed successfully.
+
+:DOWNLOAD
+go mod download
+
+ENDLOCAL

bootstrap_install_mage.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+if [[ ":$PATH:" == *":$HOME/.local/bin:"* ]]; then
+    TARGET_DIR="$HOME/.local/bin"
+else
+    TARGET_DIR="/usr/local/bin"
+    echo "Using /usr/local/bin as the installation directory. Might require sudo permissions."
+fi
+
+if ! command -v mage &> /dev/null; then
+    echo "Installing Mage to $TARGET_DIR ..."
+    GOBIN=$TARGET_DIR go install github.com/magefile/mage@latest
+fi
+
+if ! command -v mage &> /dev/null; then
+    echo "Mage installation failed."
+    echo "Please ensure that $TARGET_DIR is in your \$PATH."
+    exit 1
+fi
+
+echo "Mage installed successfully."
+
+go mod download