Add podspec

react-native-amap3d.podspec

+require 'json'
+
+package = JSON.parse(File.read(File.join(__dir__, 'package.json')))
+
+Pod::Spec.new do |s|
+  s.name         = "react-native-amap3d"
+  s.version      = package['version']
+  s.summary      = "React Native AMap3D component for iOS"
+
+  s.authors      = { "qiuxiang" => "i@7c00.cc" }
+  s.homepage     = "https://github.com/qiuxiang/react-native-amap3d"
+  s.license      = "MIT"
+  s.platform     = :ios, "8.0"
+
+  s.source       = { :git => "https://github.com/qiuxiang/react-native-amap3d.git" }
+  s.source_files  = "ios/**/*.{h,m}"
+
+  s.dependency 'React'
+  s.dependency 'AMap3DMap'
+end