Shorten the 2.11.12 changelog to what users see

The changelog is user-facing, so it states the new behavior and leaves the
background to the PR description.

Author: lelia

CHANGELOG.md

@@ -2,22 +2,16 @@
 
 ## 2.11.12
 
-### Fixed: `--repo` takes a repository slug, not `owner/repo`
+### Changed: `--repo` takes a repository slug
 
-- The help text and docs said `--repo` takes `owner/repo`, but the API only
-  accepts a repository slug, which can't contain `/`. Following the docs made
-  every scan fail. The help text and docs now describe the slug, and the CLI
-  exits `1` up front with the slug to use when `--repo` contains `/`. Use
-  `--workspace` for the owner.
-- The GitLab CI example now passes `$CI_PROJECT_NAME` instead of
-  `$CI_PROJECT_PATH`, and the Slack `repos` filter example uses slugs.
+- `--repo` takes the repository slug without its owner (`my-repo`, not
+  `my-org/my-repo`). A value containing `/` now exits `1` and names the slug to
+  use. Pass the owner with `--workspace`.
 
 ### Deprecated: `--pending-head`
 
-- `--pending-head` never had any effect: a scan on the default branch becomes
-  its head scan whether or not the flag is set. It is still accepted so
-  existing pipelines keep working, but it is hidden from `--help` and logs a
-  deprecation warning. Use `--default-branch`.
+- `--pending-head` has no effect and logs a deprecation warning. Use
+  `--default-branch`.
 
 ## 2.11.11