Update changelog and notes for new release

CHANGELOG.md

@@ -8,6 +8,36 @@ This project uses [*towncrier*](https://towncrier.readthedocs.io/) and the chang
 
 <!-- towncrier release notes start -->
 
+## [1.19.0] - 2024-05-15
+
+*Backwards-incompatible change*: Because it is now possible to filter on
+multiple event types instead of just one, both API V1 and API V2 has changed
+its schema for Filter.filter. See NOTES.md for details.
+
+### Removed
+
+- Removed `"event_type"` from the V1 Filter API, it should only have been
+  available in V2 (since it was new) and it has never been in use by the
+  frontend. ([#699](https://github.com/Uninett/Argus/issues/699))
+
+### Added
+
+- Add filtering of events by a list of event types
+  ([#699](https://github.com/Uninett/Argus/issues/699))
+- Add howto about how to set up and test federated login, using GitHub as an
+  example. ([#803](https://github.com/Uninett/Argus/issues/803))
+- Extend the usefulness of `OVERRIDE_APPS` and `EXTRA_APPS` by adding support
+  for Django template engine context processors. Any context processors are
+  added to the end of the list.
+  ([#810](https://github.com/Uninett/Argus/issues/810))
+
+### Changed
+
+- Change how the description of a change event is formatted so that it is
+  always consistent (not to mention DRY).
+  ([#809](https://github.com/Uninett/Argus/issues/809))
+
+
 ## [1.18.0] - 2024-05-07
 
 

NOTES.md

@@ -3,6 +3,31 @@
 This file documents changes to Argus that are relevant for operations and
 end-users.
 
+## [1.19.0] - 2024-05-15
+
+Remember to migrate!
+
+*Backwards-incompatible change*: Because it is now possible to filter on
+multiple event types instead of just one, both API V1 and API V2 has changed
+its schema for Filter.filter.
+
+* The key `"event_type"` is gone from V1. It never should have been there in
+  the first place since it's new functionality.
+* The key `"event_type"` has been *replaced* with a new key `"event_types"` in
+  V2. Where `"event_type"` was a single string, `"event_types"` is a list of
+  strings.
+
+Luckily, the frontend at https://github.com/Uninett/argus-frontend never added
+support for this feature.
+
+Behavior does not change as the key not being set (or set to None/empty list)
+will ignore the key when sending notifications.
+
+Existing instances of `"event_type"` in the database is automatically changed
+to `"event_types"` iff `"event_type"` was not falsey. Reversing the migration
+will set `"event_type"` to the first string in `"event_types"` hence might lose
+data: *don't reverse the migration in production!*
+
 ## [1.18.0] - 2024-05-07
 
 There's a new API endpoint allowing the deletion of an existing incident and