Add Emogrifier migration guide for 5.4 (#103)

* Add Emogrifier migration guide for 5.4

see #91

* Improve phrasing in the emogrifier migration guide
* Leave out the version details for the emogrifier update
* Add missing interpunction

Co-authored-by: Matthias Schmidt <gravatronics@live.com>

diff --git a/pages/migration/wsc-53/migration_wsc-53_libraries.md b/pages/migration/wsc-53/migration_wsc-53_libraries.md
index a533fc73b4d8428af70eb7096773bea487857396..3231d54e5420c87213fd6561b67d16ef71c72314 100644 (file)
--- a/pages/migration/wsc-53/migration_wsc-53_libraries.md
+++ b/pages/migration/wsc-53/migration_wsc-53_libraries.md
@@ -12,3 +12,16 @@ No breaking changes are expected for simple uses.
 A detailed [Guzzle migration guide](https://github.com/guzzle/guzzle/blob/master/UPGRADING.md#60-to-70) can be found in the Guzzle documentation.
 
 The explicit `sink` that was recommended in the [migration guide for WSC 5.2](migration_wsc-52_libraries.html#guzzle) can now be removed, as [the Guzzle issue #2735](https://github.com/guzzle/guzzle/issues/2735) was fixed in Guzzle 7.
+
+## Emogrifier / CSS Inliner
+
+The Emogrifier library was updated from version 2.2 to 5.0.
+This update comes with a breaking change, as the `Emogrifier` class was removed.
+With the updated Emogrifier library, the `CssInliner` class must be used instead.
+
+No compatibility layer was added for the `Emogrifier` class, as the Emogrifier library's purpose was to be used within the email subsystem of WoltLab Suite.
+In case you use Emogrifier directly within your own code, you will need to adjust the usage.
+Refer to the [Emogrifier CHANGELOG](https://github.com/MyIntervals/emogrifier/blob/v5.0.0/CHANGELOG.md) and [WoltLab/WCF #3738](https://github.com/WoltLab/WCF/pull/3738) if you need help making the necessary adjustments.
+
+If you only use Emogrifier indirectly by sending HTML mail via the email subsystem then you might notice unexpected visual changes due to the improved CSS support.
+Double check your CSS declarations and particularly the specificity of your selectors in these cases.