Merge pull request #593 from vania-pooh/master

Added webdriver.io example to file upload section

docs/file-upload.adoc

@@ -31,6 +31,14 @@ driver.file_detector = LocalFileDetector()
 input.send_keys("/path/to/file/on/machine/which/runs/tests")
 ----
 
+.Uploading files with Webdriver.io
+[source,javascript]
+----
+var filePath = path.join('/path/to/file/on/machine/which/runs/tests');
+browser.uploadFile(filePath);
+browser.chooseFile("input[type='file']", filePath);
+----
+
 Read the following note if you are using Selenoid **without Docker**.
 
 NOTE: This feature is supported in WebDriver protocol by sending zipped file contents to `/file` handle. However not all driver binaries support this feature. For example this is not implemented in http://github.com/mozilla/geckodriver[Geckodriver] or https://github.com/SeleniumHQ/selenium/tree/master/cpp/iedriver[IEDriver]. When proxying requests **directly** to these drivers (i.e. when **not using Docker**) you need to start Selenoid with `-enable-file-upload` flag. In that case Selenoid will provide required API to tests. Firefox container images already include this parameter where needed.