Update README.md

Author: ccnasro

README.md

@@ -125,7 +125,8 @@ dart pub get
        ...
        ...
    end
-  post_install do |installer|
+   ...
+   post_install do |installer|
     installer.pods_project.targets.each do |target|
       flutter_additional_ios_build_settings(target)
       target.build_configurations.each do |config|
@@ -135,7 +136,7 @@ dart pub get
         config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '13.1'
       end
     end
-  end```
+   end```
 
 #### Application permissions