docs(slate-serializers): update README.md (#169)

packages/slate-serializers/README.md

@@ -1,10 +1,10 @@
 # slate-serializers
 
-This package has been split into separate packages. As more serializers are introduced, the number of dependencies increase. It makes sense to maintain separate packages to keep the serializers as efficient as possible for their desired use case.
+This package has been split into separate packages.
 
 There is no need to change - `slate-serializers` will continue to be maintained alongside the new serializers. However, upgrading will keep the dependency tree minimal for your project.
 
-Original docs available at [packages/slate-serializers/docs/original.md](packages/slate-serializers/docs/original.md).
+Original docs available at [packages/slate-serializers/docs/original.md](https://github.com/thompsonsj/slate-serializers/blob/main/packages/slate-serializers/docs/original.md).
 
 ## New packages
 
@@ -24,3 +24,7 @@ If importing configuration objects, change the name as follows.
 ### DOM serializer
 
 Change import from `slate-serializers` to `@slate-serializers/dom`.
+
+## Rationale for splitting the packages
+
+As more serializers are introduced, the number of dependencies increase. It makes sense to maintain separate packages to keep the serializers as efficient as possible for their desired use case.