fixed typo; added example of usage vmbackup in docker-compose (#1237)

docs/vmbackup.md

@@ -171,6 +171,23 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
   -customS3Endpoint=https://s3-fips.us-gov-west-1.amazonaws.com
 ```
 
+* Usage with official [docker-compose](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/deployment/docker/docker-compose.yml) `vmsingle` instance:
+```
+  vmbackup:
+    image: victoriametrics/vmbackup:v1.58.0
+    volumes:
+      - vmdata:/storage
+      - /data:/data
+    command:
+      - '--storageDataPath=/storage'
+      - '--snapshot.createURL=http://victoriametrics:8428/snapshot/create'
+      - '--snapshotName=your_snapshot_name_here'
+      - '--dst=fs:///data'
+    networks:
+      - vm_net
+```
+Note that you need to specify `--snapshot.createURL`  to make a snapshot.
+
 * Run `vmbackup -help` in order to see all the available options:
 
 ```
@@ -220,9 +237,9 @@ See [this article](https://medium.com/@valyala/speeding-up-backups-for-big-time-
   -origin string
     	Optional origin directory on the remote storage with old backup for server-side copying when performing full backup. This speeds up full backups
   -snapshot.createURL string
-    	VictoriaMetrics create snapshot url. When this is given a snapshot will automatically be created during backup. Example: http://victoriametrics:8428/snaphsot/create
+    	VictoriaMetrics create snapshot url. When this is given a snapshot will automatically be created during backup. Example: http://victoriametrics:8428/snapshot/create
   -snapshot.deleteURL string
-    	VictoriaMetrics delete snapshot url. Optional. Will be generated from -snapshot.createURL if not provided. All created snaphosts will be automatically deleted. Example: http://victoriametrics:8428/snaphsot/delete
+    	VictoriaMetrics delete snapshot url. Optional. Will be generated from -snapshot.createURL if not provided. All created snapshots will be automatically deleted. Example: http://victoriametrics:8428/snapshot/delete
   -snapshotName string
     	Name for the snapshot to backup. See https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-work-with-snapshots
   -storageDataPath string