[DOCS] Remove references to removed changelog

docs/reference/index-shared4.asciidoc

@@ -7,4 +7,4 @@ include::glossary.asciidoc[]
 
 include::release-notes/highlights.asciidoc[]
 
-include::{docdir}/../CHANGELOG.asciidoc[]
+include::release-notes.asciidoc[]

docs/reference/release-notes/highlights-7.0.0.asciidoc

@@ -6,4 +6,4 @@
 
 coming[7.0.0]
 
-See also <<breaking-changes-7.0>> and <<release-notes-7.0.0>>. 
+See also <<breaking-changes-7.0>> and <<release-notes-7.0.0-alpha1>>.