Add download link and 20.10.4 template (#1725)

Signed-off-by: Tim Beiko <t.beiko23@gmail.com>

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog
 
+## 20.10.4
+
+### Additions and Improvements
+
+### Bug Fixes
+
+#### Previously identified known issues
+
+- [Fast sync when running Besu on cloud providers](KNOWN_ISSUES.md#fast-sync-when-running-besu-on-cloud-providers)
+- [Privacy users with private transactions created using v1.3.4 or earlier](KNOWN_ISSUES.md#privacy-users-with-private-transactions-created-using-v134-or-earlier)
+
+### Download link
+TBA
+
 ## 20.10.3
 
 ### Additions and Improvements
@@ -17,6 +31,10 @@
 - [Fast sync when running Besu on cloud providers](KNOWN_ISSUES.md#fast-sync-when-running-besu-on-cloud-providers)
 - [Privacy users with private transactions created using v1.3.4 or earlier](KNOWN_ISSUES.md#privacy-users-with-private-transactions-created-using-v134-or-earlier)
 
+### Download link
+https://dl.bintray.com/hyperledger-org/besu-repo/besu-20.10.3.zip
+sha256: `b5f46d945754dedcbbb1e5dd96bf2bfd13272ff09c6a66c0150b979a578f4389`
+
 ## 20.10.2
 
 ### Additions and Improvements