Added C# Sendkeys code example (#30)

Author: alenros

docs_source_files/content/webdriver/keyboard.en.md

@@ -44,7 +44,14 @@ driver.get("http://www.google.com")
 driver.find_element_by_name("q").send_keys("webdriver"+Keys.ENTER)
   {{< / code-panel >}}
   {{< code-panel language="csharp" >}}
-// We don't have a C# code sample yet -  Help us out and raise a PR
+using (var driver = new FirefoxDriver())
+{
+    // Navigate to Url
+    driver.Navigate().GoToUrl("https://google.com");
+
+    // Enter text "q" and perform keyboard action "Enter"
+    driver.FindElement(By.Name("q")).SendKeys("q" + Keys.Enter);
+}
   {{< / code-panel >}}
   {{< code-panel language="ruby" >}}
 require 'selenium-webdriver'
@@ -101,4 +108,4 @@ class HelloSelenium {
     }
 }
   {{< / code-panel >}}
-{{< / code-tab >}}
+{{< / code-tab >}}