misc: changed "Twitter" to "𝕏 (Twitter)" in README.md (#10861)

* Update README.md

changed "Twitter" to "𝕏 (Twitter)"

* Update README.md

added links in alphabetical order and added mastodon/fediverse link too.

* Update README.md

changed http to https

README.md

@@ -60,12 +60,11 @@ Click on these badges to see how you might be able to help:
 ## How to Share
 
 <div align="left" markdown="1">
-
-<a href="http://twitter.com/intent/tweet?text=https://github.com/EbookFoundation/free-programming-books%0AFree%20Programming%20Books">Share on Twitter</a><br>
 <a href="https://www.facebook.com/share.php?u=https%3A%2F%2Fgithub.com%2FEbookFoundation%2Ffree-programming-books&p[images][0]=&p[title]=Free%20Programming%20Books&p[summary]=">Share on Facebook</a><br>
 <a href="http://www.linkedin.com/shareArticle?mini=true&url=https://github.com/EbookFoundation/free-programming-books&title=Free%20Programming%20Books&summary=&source=">Share on LinkedIn</a><br>
+<a href="https://toot.kytta.dev/?mini=true&url=https://github.com/EbookFoundation/free-programming-books&title=Free%20Programming%20Books&summary=&source=">Share on Mastodon/Fediverse</a><br>    
 <a href="https://t.me/share/url?url=https://github.com/EbookFoundation/free-programming-books">Share on Telegram</a><br>
-
+<a href="https://twitter.com/intent/tweet?text=https://github.com/EbookFoundation/free-programming-books%0AFree%20Programming%20Books">Share on 𝕏 (Twitter)</a><br>
 </div>
 
 ## Resources