[DOCS] Add admin changelog for YAML

Documentation/Admins/Changelog/60149-Change-ReplaceSpycWithSymfonyYaml.md

@@ -0,0 +1,49 @@
+# 60149 Change Replace Spyc with symfony/yaml
+
+Issue https://projekte.in2code.de/issues/60149
+
+## Description
+
+in2publish_core uses a YAML file for configuration since it was first develop in 2015. YAML has not been established as
+a configuration language back then, so it was necessary to ship a YAML parser with the extension. Time flew by and some
+TYPO3 versions later, TYPO3 uses YAML for site configuration, the Form Framework, CKE Editor configuration, and more.
+We have not required any YAML parser via composer, because we also supported TYPO3 in non-composer installations.
+
+So eventually, TYPO3 requires a YAML parser, too. We can rely on the implementation shipped with TYPO3 to reduce the
+code we have to maintain, which we did in in2publish_core v12.3.0. We are now using the YAML parser shipped with TYPO3.
+
+## Impact
+
+symfony/yaml does not support multiple documents and a specific list type. You will have to change your configuration or
+else you will experience exceptions and probably unwanted side effects.
+
+## Affected Installations
+
+Possibly all, probably only those who do not have the Content Publisher Enterprise Edition installed.
+
+## Migration
+
+1. Remove the "end of directives marker" `---` from any Content Publisher configuration YAML file.
+2. Replace block collections with arrays (see Example #1 Replace block collections with arrays)
+
+## Examples
+
+### #1 Replace block collections with arrays
+Before:
+```yaml
+    permission:
+      definition:
+        2:
+          3
+          4
+          5
+          6
+          7
+          8
+```
+After
+```yaml
+    permission:
+      definition:
+        2: [3,4,5,6,7,8]
+```