Update API documentation

Signed-off-by: Christian Wolf <github@christianwolf.email>

docs/dev/api/changelog/0.md

@@ -16,6 +16,8 @@ See also [the section](#split-and-rename-api-endpoints).
 
 ## Version 0.1.0 - cookbook v0.9.15 - 2022-09-08
 
+See [API specification](../0.1.0/index.html)
+
 ### Split and rename API endpoints
 There is a security issue with the previous API version 0.4.0, see [this description](https://github.com/nextcloud/cookbook/issues/1179).
 As a result, **all** endpoints need a renaming to be able to  fix the security issue.