Added twitter link to website. Fixes #467.

_i18n/de.yml

@@ -110,7 +110,7 @@ footer:
   id: links
   irma_alt: IRMA logo
   irma_headline: Stiftung Privacy by Design
-  irma_content: IRMA wird von der <a href="https://privacybydesign.foundation/" target="_blank">Stiftung Privacy by Design</a> entwickelt. Eine detailliertere Erklärung der Funktionsweise von IRMA bietet die Stiftung Privacy by Design auf ihrer eigenen <a href="https://privacybydesign.foundation/irma-uitleg/" target="_blank">Webseite</a>.
+  irma_content: IRMA wird von der <a href="https://privacybydesign.foundation/" target="_blank">Stiftung Privacy by Design</a> entwickelt. Eine detailliertere Erklärung der Funktionsweise von IRMA bietet die Stiftung Privacy by Design auf ihrer eigenen <a href="https://privacybydesign.foundation/irma-uitleg/" target="_blank">Webseite</a>. Für aktuelle Informationen <br/> <a href="https://twitter.com/irma_privacy?ref_src=twsrc%5Etfw" class="twitter-follow-button" data-lang="de" data-show-count="false">Follow @irma_privacy</a><script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>.
   doc_headline: Docs
   doc_content: Entwickler, die mit IRMA arbeiten möchten, können hier die <a href="https://irma.app/docs" target="_blank">Dokumentation</a> finden.
   github_headline: GitHub

_i18n/en.yml

@@ -107,6 +107,7 @@ footer:
   irma_content: IRMA is produced and run by the <a href="https://privacybydesign.foundation/en" target="_blank">Privacy
     by Design</a> Foundation, which provides extensive
     <a href="https://privacybydesign.foundation/irma-explanation/" target="_blank">explanations</a>.
+    For recent information <br/> <a href="https://twitter.com/irma_privacy?ref_src=twsrc%5Etfw" class="twitter-follow-button" data-lang="en" data-show-count="false">Follow @irma_privacy</a><script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>.
   doc_headline: Docs
   doc_content: Developers who wish to work with IRMA can check out IRMA's technical <a href="https://irma.app/docs" target="_blank">documentation</a>.
   github_headline: GitHub

_i18n/nl.yml

@@ -225,10 +225,11 @@ footer:
   irma_headline: Privacy by Design Foundation
   irma_content: IRMA wordt gemaakt door de stichting <a href="https://privacybydesign.foundation/" target="_blank">Privacy
     by Design</a>. Uitgebreidere uitleg over de werking van IRMA wordt gegeven door de stichting Privacy by Design op
-    haar eigen  <a href="https://privacybydesign.foundation/irma-uitleg/" target="_blank">website</a>.
+    haar eigen  <a href="https://privacybydesign.foundation/irma-uitleg/" target="_blank">website</a>. Voor actuele
+    informatie <br/> <a href="https://twitter.com/irma_privacy?ref_src=twsrc%5Etfw" class="twitter-follow-button" data-lang="nl" data-show-count="false">Follow @irma_privacy</a><script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>.
   doc_headline: Docs
   doc_content: Ontwikkelaars die met IRMA willen werken kunnen terecht op de technische
     <a href="https://irma.app/docs" target="_blank">documentatie</a> pagina.
   github_headline: GitHub
   github_content: Mensen die de software van IRMA willen bekijken of willen bijdragen aan IRMA kunnen
-    terecht op <a href="https://github.com/privacybydesign" target="_blank">GitHub</a>.
\ No newline at end of file
+    terecht op <a href="https://github.com/privacybydesign" target="_blank">GitHub</a>.