Releases: add 0.21.0

Tree-SHA512: 2ce172da98c1b7a5278b0e50701b4e178eea69093ee6382054b0d7a9fb8519e24be14e46ef837007553fe8fdf93c56208f0379ec0f429f031b66e6851a4b9cfa

Author: laanwj

_posts/en/posts/2021-01-14-release-0.21.0.md

@@ -0,0 +1,30 @@
+---
+title: Bitcoin Core 0.21.0 Released
+name: blog-release-0.21.0
+id: en-blog-release-0.21.0
+lang: en
+type: posts
+layout: post
+
+## If this is a new post, reset this counter to 1.
+version: 1
+
+## Only true if release announcement or security annoucement.  English posts only
+announcement: 1
+
+excerpt: >
+  Bitcoin Core 0.21.0 is now available with multiple improvements.
+---
+Bitcoin Core version 0.21.0 is now available for [download][download
+page]. For a complete list of changes in this new major version release,
+please see the [release notes][].
+
+If have any questions, please stop by the #bitcoin IRC chatroom
+([IRC][irc], [web][web irc]) and we’ll do our best to help you.
+
+[release notes]: /en/releases/0.21.0/
+[IRC]: irc://irc.freenode.net/bitcoin
+[web irc]: https://webchat.freenode.net/#bitcoin
+[download page]: /en/download
+
+{% include references.md %}