Update post-release changelog links

CHANGELOG.md

@@ -8,8 +8,21 @@ Useful links: Docsy [releases][] & [tags][]. Jump to the [latest][] release.
 
 For a list of issues targeted for the next release, see the [22Q2][] milestone.
 
-## 0.6.0 - next planned release (unpublished yet)
+## 0.7.0 - next planned release (unpublished yet)
 
+**New**:
+
+**Breaking changes**:
+
+**Other changes**:
+
+## [0.6.0][]
+
+For the full list of the changes found in this release, see the [release
+notes][0.6.0].
+
+With this release we declare a feature freeze while we migrate to the newest
+Bootstrap version. See [the announcement][bs-announcement] for more information.
 
 **New**:
 
@@ -177,6 +190,7 @@ For a full list of the changes to this release, see the [release notes][0.x.y].
 
 [@deining]: https://github.com/deining
 [@lisafc]: https://github.com/LisaFC
+[0.6.0]: https://github.com/google/docsy/releases/v0.6.0
 [0.5.1]: https://github.com/google/docsy/releases/v0.5.1
 [0.5.0]: https://github.com/google/docsy/releases/v0.5.0
 [0.4.0]: https://github.com/google/docsy/releases/v0.4.0
@@ -188,3 +202,4 @@ For a full list of the changes to this release, see the [release notes][0.x.y].
 [latest]: https://github.com/google/docsy/releases/latest
 [releases]: https://github.com/google/docsy/releases
 [tags]: https://github.com/google/docsy/tags
+[bs-announcement]: https://github.com/google/docsy/discussions/1308