Remove webdriver-spec.html from WebDriver URLs (#212)

It redirects.

Author: foolip

index.src.html

@@ -100,7 +100,7 @@ <h1>Reporting API</h1>
 spec: ECMASCRIPT; urlPrefix: https://tc39.github.io/ecma262/
   type: dfn
     text: Realm
-spec: webdriver; urlPrefix: https://w3c.github.io/webdriver/webdriver-spec.html#
+spec: webdriver; urlPrefix: https://w3c.github.io/webdriver/#
   type: dfn
     text: current browsing context; url: dfn-current-browsing-context
     text: handle any user prompts; url: dfn-handle-any-user-prompts