Format the docs according to style guide

docs/api/web-contents.md

@@ -147,7 +147,8 @@ Returns:
   `new-window`, `save-to-disk` and `other`.
 * `options` Object - The options which will be used for creating the new
   `BrowserWindow`.
-* `additional_features` Array - The non-standard features (features not handled by Chromium or Electron) given to `window.open()`. 
+* `additionalFeatures` Array - The non-standard features (features not handled
+  by Chromium or Electron) given to `window.open()`.
 
 Emitted when the page requests to open a new window for a `url`. It could be
 requested by `window.open` or an external link like `<a target='_blank'>`.

docs/api/window-open.md

@@ -26,9 +26,11 @@ The `features` string follows the format of standard browser, but each feature
 has to be a field of `BrowserWindow`'s options.
 
 **Notes:**
-* Node integration will always be disabled in the opened `window` if it
-is disabled on the parent window.
-* Non-standard features (that are not handled by Chromium or Electron such `this-is-not-a-standard-feature`) given in features will be passed to any registered `webContent`'s `new-window` event handler in the `additional_features` argument.
+* Node integration will always be disabled in the opened `window` if it is
+  disabled on the parent window.
+* Non-standard features (that are not handled by Chromium or Electron) given in
+  `features` will be passed to any registered `webContent`'s `new-window` event
+  handler in the `additionalFeatures` argument.
 
 ### `window.opener.postMessage(message, targetOrigin)`