Update release notes for 16.20.5 and 16.20.6 (#4759)

CHANGELOG.md

@@ -201,6 +201,32 @@
 - Use a universal static path for both documentation and volto repos. @stevepiercy [#4376](https://github.com/plone/volto/issues/4376)
 
 
+## 16.20.6 (2023-05-12)
+
+### Bugfix
+
+- Fix language negotiation for language codes that include a region (e.g. `pt-br`). @davisagli [#4644](https://github.com/plone/volto/issues/4644)
+
+
+## 16.20.5 (2023-05-12)
+
+### Bugfix
+
+- Apply suggestion from browser for password field @lord2anil [#3990](https://github.com/plone/volto/issues/3990)
+- The tabs for the add page was unresponsive on mobile devices. Fixed this by changing flex-wrap property. @sudhanshu1309 [#4506](https://github.com/plone/volto/issues/4506)
+- (fix):Object.normaliseMail: Cannot read properties of null @dobri1408 [#4558](https://github.com/plone/volto/issues/4558)
+
+### Internal
+
+- Upgrade to Plone 6.0.4 @sneridagh [#4743](https://github.com/plone/volto/issues/4743)
+
+### Documentation
+
+- Added documentation regarding the static middleware. @BhardwajAditya-github [#4518](https://github.com/plone/volto/issues/4518)
+- Backport most documentation differences from `master` to `16.x.x`. @stevepiercy [#4727](https://github.com/plone/volto/issues/4727)
+- Fix link in Volto, remove from linkcheck ignore in Documentation. @stevepiercy [#4742](https://github.com/plone/volto/issues/4742)
+
+
 ## 16.20.4 (2023-04-20)
 
 ### Bugfix