Update Changelog for 20.4.0

changelog.txt

@@ -1,7 +1,6 @@
 == Changelog ==
 
-= 20.4.0-rc.1 =
-
+= 20.4.0 =
 
 ## Changelog
 
@@ -18,6 +17,7 @@
 #### Block Library
 - Post Navigation Link: Enable all non-interactive formats. ([69325](https://github.com/WordPress/gutenberg/pull/69325))
 - Pullquote: Adding missing alignment style. ([68121](https://github.com/WordPress/gutenberg/pull/68121))
+- Query Loop: Add `menu_order` as sorting option. ([68781](https://github.com/WordPress/gutenberg/pull/68781))
 
 #### Site Editor
 - Enhance 404 message styling. ([69234](https://github.com/WordPress/gutenberg/pull/69234))
@@ -182,6 +182,8 @@ The following contributors merged PRs in this release:
 @adamsilverstein @afercia @alexchrysovergis @andreawetzel @benazeer-ben @carolinan @DAreRodz @davilera @fabiankaegy @felixarntz @himanshupathak95 @huubl @im3dabasia @Infinite-Null @jonathanbossenger @juanmaguitar @kellymears @Mamaduka @ockham @Rishit30G @SainathPoojary @shail-mehta @shimotmk @singhakanshu00 @snehapatil2001 @stokesman @Sukhendu2002 @swissspidy @t-hamano @yogeshbhutkar
 
 
+
+
 = 20.0.3 =
 
 ## Changelog