Update README.md

pkgs/yaml/README.md

diff --git a/pkgs/yaml/README.md b/pkgs/yaml/README.md
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--- a/pkgs/yaml/README.md
+++ b/pkgs/yaml/README.md
@@ -1,4 +1,4 @@
-A parser for [YAML](http://www.yaml.org/).
+A parser for [YAML](https://yaml.org/).
 
 [![Pub Package](https://img.shields.io/pub/v/yaml.svg)](https://pub.dev/packages/yaml)
 [![Build Status](https://travis-ci.org/dart-lang/yaml.svg?branch=master)](https://travis-ci.org/dart-lang/yaml)