Merge branch '1.0' into 2.0

* 1.0:
  Generate changelog for v1.0.0
  [Composer] Fix branch alias
  Remove note about migrations from UPGRADE file

Author: GSadee

composer.json

@@ -87,7 +87,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-main": "2.0-dev"
+            "dev-2.0": "2.0-dev"
         }
     },
     "prefer-stable": true