docs: auto generate backend options documentation

This inserts the output of "rclone help backend xxx" into the help
pages for each backend.

docs/content/jottacloud.md

@@ -124,8 +124,76 @@ To view your current quota you can use the `rclone about remote:`
 command which will display your usage limit (unless it is unlimited)
 and the current usage.
 
-<!--- autogenerated options start - edit in backend/backend.go options  -->
-<!--- autogenerated options stop  -->
+<!--- autogenerated options start - DO NOT EDIT, instead edit fs.RegInfo in backend/jottacloud/jottacloud.go then run make backenddocs -->
+### Standard Options
+
+Here are the standard options specific to jottacloud (JottaCloud).
+
+#### --jottacloud-user
+
+User Name
+
+- Config:      user
+- Env Var:     RCLONE_JOTTACLOUD_USER
+- Type:        string
+- Default:     ""
+
+#### --jottacloud-pass
+
+Password.
+
+- Config:      pass
+- Env Var:     RCLONE_JOTTACLOUD_PASS
+- Type:        string
+- Default:     ""
+
+#### --jottacloud-mountpoint
+
+The mountpoint to use.
+
+- Config:      mountpoint
+- Env Var:     RCLONE_JOTTACLOUD_MOUNTPOINT
+- Type:        string
+- Default:     ""
+- Examples:
+    - "Sync"
+        - Will be synced by the official client.
+    - "Archive"
+        - Archive
+
+### Advanced Options
+
+Here are the advanced options specific to jottacloud (JottaCloud).
+
+#### --jottacloud-md5-memory-limit
+
+Files bigger than this will be cached on disk to calculate the MD5 if required.
+
+- Config:      md5_memory_limit
+- Env Var:     RCLONE_JOTTACLOUD_MD5_MEMORY_LIMIT
+- Type:        SizeSuffix
+- Default:     10M
+
+#### --jottacloud-hard-delete
+
+Delete files permanently rather than putting them into the trash.
+
+- Config:      hard_delete
+- Env Var:     RCLONE_JOTTACLOUD_HARD_DELETE
+- Type:        bool
+- Default:     false
+
+#### --jottacloud-unlink
+
+Remove existing public link to file/folder with link command rather than creating.
+Default is false, meaning link command will create or retrieve public link.
+
+- Config:      unlink
+- Env Var:     RCLONE_JOTTACLOUD_UNLINK
+- Type:        bool
+- Default:     false
+
+<!--- autogenerated options stop -->
 
 ### Limitations ###