Added new database rustydb

doc/cli.md

@@ -0,0 +1,29 @@
+# CLI
+
+You can find different tools for migrating things, checking your Etherpad health in the bin directory.
+One of these is the migrateDB command. It takes two settings.json files and copies data from one source to another one.
+In this example we migrate from the old dirty db to the new rustydb engine. So we copy these files to the root of the etherpad-directory.
+
+````json
+{
+  "dbType": "dirty",
+  "dbSettings": {
+    "filename": "./var/rusty.db"
+  }
+}
+````
+
+
+
+````json
+{
+  "dbType": "rustydb",
+  "dbSettings": {
+    "filename": "./var/rusty2.db"
+  }
+}
+````
+
+
+After that we need to move the data from dirty to rustydb.
+Therefore, we call `pnpm run migrateDB --file1 test1.json --file2 test2.json` with these two files in our root directories. After some time the data should be copied over to the new database.