Add post-release "complete versioning details" link.

Author: abernix

CHANGELOG.md

@@ -10,6 +10,8 @@ The version headers in this history reflect the versions of Apollo Server itself
 
 ### v2.9.3
 
+> [See complete versioning details.](https://github.com/apollographql/apollo-server/commit/a1fbf95fc01739d5cbaa59919149bb85c563fdaa)
+
 - `apollo-server-express`: Add direct dependency on `express` to allow for usage of `express.Router` for `getMiddleware` functionality (from [#2435](https://github.com/apollographql/apollo-server/pull/2435)).  Previously, unlike other server integration packages, `apollo-server-express` did not directly need `express` as a dependency since it only relied on `express` for TypeScript typings. [Issue #3238](https://github.com/apollographql/apollo-server/issues/3238) [PR #3239](https://github.com/apollographql/apollo-server/pull/3239)
 - `apollo-server-lambda`: Add `@types/aws-lambda` as a direct dependency to `apollo-server-express` to allow usage of its typings without needing to separately install it. [Issue #2351](https://github.com/apollographql/apollo-server/issue/2351) [PR #3242](https://github.com/apollographql/apollo-server/pull/3242)