Correct typos in docs

docs/api/app.md

@@ -424,7 +424,7 @@ Clears the recent documents list.
 
 This method sets the current executable as the default handler for a protocol
 (aka URI scheme). It allows you to integrate your app deeper into the operating
-system. Once registered, all links with `your-protocol://` will be openend with
+system. Once registered, all links with `your-protocol://` will be opened with
 the current executable. The whole link, including protocol, will be passed to
 your application as a parameter.
 

docs/api/web-contents.md

@@ -325,8 +325,8 @@ Returns:
 
 * `event` Event
 * `params` Object
-  * `x` Integer - x coodinate
-  * `y` Integer - y coodinate
+  * `x` Integer - x coordinate
+  * `y` Integer - y coordinate
   * `linkURL` String - URL of the link that encloses the node the context menu
     was invoked on.
   * `linkText` String - Text associated with the link. May be an empty

docs/api/web-frame.md

@@ -141,7 +141,7 @@ previous navigation).
 
 Note that blindly calling this method probably makes Electron slower since it
 will have to refill these emptied caches, you should only call it if an event
-in your app has occured that makes you think your page is actually using less
+in your app has occurred that makes you think your page is actually using less
 memory (i.e. you have navigated from a super heavy page to a mostly empty one,
 and intend to stay there).