[#505] docs: Add example of uploading file using presigned URL

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

docs/authmate.md

@@ -349,6 +349,25 @@ $ frostfs-s3-authmate generate-presigned-url --endpoint http://localhost:8084 \
 }
 ```
 
+### Upload file with presigned URL
+
+1. Generate presigned URL to upload object `obj` to bucket `presigned`
+
+   ```shell
+   $ frostfs-s3-authmate generate-presigned-url --endpoint http://localhost:8084 \
+   --method put --bucket presigned --object obj --lifetime 30s
+   
+   {
+     "URL": "http://localhost:8084/presigned/obj?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=CYfbvKwSC9VNvttj5snyEZ5Ttr2VaBabpw7mRuEzNXyw09ewUERj6MGDKfyckfg5VZ39GfXbwLwz62UPVeRxhJDet%2F20241029%2Fdefault%2Fs3%2Faws4_request&X-Amz-Date=20241029T145726Z&X-Amz-Expires=30&X-Amz-SignedHeaders=host&X-Amz-Signature=2bb13b3e6448968219ad95147debe49e37bce5ce3ed1344c4015f43cb444a956"
+   }
+   ```
+   
+2. Upload file using `curl`
+
+   ```shell
+   curl --upload-file /path/to/file 'http://localhost:8084/presigned/obj?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=CYfbvKwSC9VNvttj5snyEZ5Ttr2VaBabpw7mRuEzNXyw09ewUERj6MGDKfyckfg5VZ39GfXbwLwz62UPVeRxhJDet%2F20241029%2Fdefault%2Fs3%2Faws4_request&X-Amz-Date=20241029T145726Z&X-Amz-Expires=30&X-Amz-SignedHeaders=host&X-Amz-Signature=2bb13b3e6448968219ad95147debe49e37bce5ce3ed1344c4015f43cb444a956'
+   ```
+
 ### AWS CLI
 
 You can also can get the presigned URL (only for GET) using aws cli v2: