feat!: Move assets outside of the API endpoints

Close #4

src/openapi.yaml

@@ -23,8 +23,6 @@ paths:
     $ref: ./paths/lecturers.yaml
   /api/module-history:
     $ref: ./paths/module-history.yaml
-  /api/changelog.html:
-    $ref: ./paths/changelog-html.yaml
   /api/{semester}/config:
     $ref: ./paths/{semester}/config.yaml
   /api/{semester}/changes:
@@ -35,5 +33,8 @@ paths:
     $ref: ./paths/{semester}/{version}/classes.yaml
   /api/{semester}/{version}/config:
     $ref: ./paths/{semester}/{version}/config.yaml
-  /api/{semester}/{version}/klassen.pdf:
+
+  /assets/changelog.html:
+    $ref: ./paths/changelog-html.yaml
+  /assets/{semester}/{version}/klassen.pdf:
     $ref: ./paths/{semester}/{version}/klassen-pdf.yaml