[Feat] add support cocoapods

Author: zhgchgli0718

ZMarkupParser.podspec

@@ -0,0 +1,12 @@
+Pod::Spec.new do |s|
+  s.name             = 'ZMarkupParser'
+  s.version          = '1.0.0'
+  s.summary          = 'ZMediumToMarkdown lets you download Medium post and convert it to markdown format easily.'
+  s.homepage         = 'https://github.com/ZhgChgLi/ZMediumToMarkdown'
+  s.license          = { :type => 'MIT', :file => 'LICENSE.md' }
+  s.author           = { 'ZhgChgLi' => '[email protected]' }
+  s.source           = { :git => 'https://github.com/ZhgChgLi/ZMediumToMarkdown.git', :tag => s.version.to_s }
+  s.ios.deployment_target = '10.0'
+  s.swift_version = '5.0'
+  s.source_files = 'Sources/ZMarkupParser/**/*'
+end