Updated Changelog (markdown)

Changelog.md

@@ -7,7 +7,8 @@ This change log tracks the releases on our [pilot server](https://recodex.mff.cu
 | 3.2.2021      |  v1.25.0 |  v1.25.0 |  v1.7.2  |  v1.3.0  |  ------  |  v1.0.0  |  v1.1.0  |
 
 ## TBA
-[[Major Release: ReCodEx 2.0]]
+> Major release 2.0
+The major release and migration change is summarized in [[Major Release: ReCodEx 2.0|a separate page]].
 
 ## 27.3.2021
 - CAS/LDAP registration and authentication delegated to external authentication adapter-application.