Update README.md

Author: erikw

README.md

@@ -1,4 +1,4 @@
-# NestedText Ruby Library [![Tweet](https://img.shields.io/twitter/url/http/shields.io.svg?style=social)](https://twitter.com/intent/tweet?text=NestedText,%20the%20human%20friendly%20data%20format,%20has%20a%20now%20a%20ruby%20library%20for%20easy%20encoding%20and%20decoding&url=https://github.com/erikw/nestedtext-ruby&via=erik_westrup&hashtags=nestedtext,ruby,gem)
+# NestedText Ruby Library [![Post on X](https://img.shields.io/twitter/url/http/shields.io.svg?style=social)](https://x.com/intent/tweet?text=NestedText,%20the%20human%20friendly%20data%20format,%20has%20a%20now%20a%20ruby%20library%20for%20easy%20encoding%20and%20decoding&url=https://github.com/erikw/nestedtext-ruby&via=erik_westrup&hashtags=nestedtext,ruby,gem)
 [![Gem Version](https://badge.fury.io/rb/nestedtext.svg)](https://badge.fury.io/rb/nestedtext)
 [![Gem Downloads](https://img.shields.io/gem/dt/nestedtext?label=gem%20downloads)](https://rubygems.org/gems/nestedtext)
 [![Documentation](https://img.shields.io/badge/docs-API-informational?logo=readthedocs&logoColor=violet)](https://www.rubydoc.info/gems/nestedtext/NestedText)