docs for server/janitor/enable_asset_cleanup (see #58721)

Author: mad-pf

content/sysadmin/configuration/easydb-server.yml/available-variables/_index.en.md

@@ -256,6 +256,7 @@ smtp:
 | ⇨`janitor` | | | |
 | ⇨⇨`eas_sync_commit`                  | Boolean        | No       | Enable asset status sync to EAS. Assets not linked in easydb are removed by EAS janitor | `true` |
 | ⇨⇨`enabled`                          | Boolean        | Yes      | Whether the janitor is running | `true` |
+| ⇨⇨`enable_asset_cleanup`             | Boolean        | No       | If enabled, assets not linked anymore are removed from database, the EAS may delete them (since version 5.90) | true |
 | ⇨⇨`interval`                         | Integer        | Yes      | How often the Janitor runs (every X seconds) | `600` (10 minutes) |
 | ⇨⇨`max_age`                          | Integer        | Yes      | When a file expires (after X seconds) | `259200` (3 days) |
 | ⇨`mailer` | | | |