Add changelog entry

Niclas Kristek · Niclas Kristek · commit b346a977c836 · 2020-10-05T16:24:09.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # master
 *Please add new entries at the top.*
+1. Add `ExpressibleByNilLiteral` constraint to `OptionalProtocol` (#805, kudos to @nkristek)
 
 # 6.4.0
 1. Bump min. deployment target to iOS 9 when using swift packages to silence Xcode 12 warnings. Update Quick & Nibmle to the latest version when using swift packages.
