Update changelog for 1.28.6

Signed-off-by: Anca Iordache <[email protected]>

CHANGELOG.md

@@ -1,6 +1,25 @@
 Change log
 ==========
 
+1.28.6 (2021-03-23)
+-------------------
+
+[List of PRs / issues for this release](https://github.com/docker/compose/milestone/57?closed=1)
+
+### Bugs
+
+- Make `--env-file` relative to the current working directory and error out for invalid paths. Environment file paths set with `--env-file` are relative to the current working directory while the default `.env` file is located in the project directory which by default is the base directory of the Compose file.
+
+- Fix missing service property `storage_opt` by updating the compose schema
+
+- Fix build `extra_hosts` list format
+
+- Remove extra error message on `exec`
+
+### Miscellaneous
+
+- Add `compose.yml` and `compose.yaml` to default filename list
+
 1.28.5 (2021-02-25)
 -------------------