docs: update Windows service snippet (#260)

README.md

@@ -75,22 +75,22 @@ Feel free to revisit and add more drivers as required. There's also the `custom`
 ## Run as a Windows service
 
 If you run SQL Exporter from Windows, it might come in handy to register it as a service to avoid interactive sessions.
-It is **important** to define `-config.file` parameter to load the configuration file. The other settings can be added
-as well. The registration itself is performed with Powershell or CMD (make sure you run them as Administrator):
+It is **important** to define `--config.file` parameter to load the configuration file. The other settings can be added
+as well. The registration itself is performed with Powershell or CMD (make sure you run it as Administrator):
 
 Powershell:
 
 ```powershell
 New-Service -name "SqlExporterSvc" `
--BinaryPathName "%SQL_EXPORTER_PATH%\sql_exporter.exe -config.file %SQL_EXPORTER_PATH%\sql_exporter.yml" `
+-BinaryPathName "%SQL_EXPORTER_PATH%\sql_exporter.exe --config.file %SQL_EXPORTER_PATH%\sql_exporter.yml" `
 -StartupType Automatic `
 -DisplayName "Prometheus SQL Exporter"
 ```
 
 CMD:
 
 ```shell
-sc.exe create SqlExporterSvc binPath= "%SQL_EXPORTER_PATH%\sql_exporter.exe -config.file %SQL_EXPORTER_PATH%\sql_exporter.yml" start= auto
+sc.exe create SqlExporterSvc binPath= "%SQL_EXPORTER_PATH%\sql_exporter.exe --config.file %SQL_EXPORTER_PATH%\sql_exporter.yml" start= auto
 ```
 
 `%SQL_EXPORTER_PATH%` is a path to the SQL Exporter binary executable. This document assumes that configuration files