Merge branch 'module-for-additive' into no-group

Author: Ericson2314

ChangeLog.md

@@ -20,6 +20,9 @@
 
 ## Unreleased
 
+* `Additive` now lives in `Data.Semigroup.Additive`, but is still reexported
+  from `Data.Patch` for compatability.
+
 * Rewrite `PatchMapWithMove` in terms of `PatchMapWithPatchingMove`.
   Care is taken to make this not a breaking change.
   In particular, `PatchMapWithMove` is a newtype of `PatchMapWithPatchingMove`, as is the `NodeInfo` and `From` of `PatchMapWithPatchingMove`'s versions of those.