Fiy a few small typos in the Popups documentation

Change-Id: I0f02a41977eef0e1bf8fe4fc924c32e17ef78dd7

README.md

@@ -1,4 +1,4 @@
-![Popups](images/popups.svg)
+![Popups](./popups.svg)
 
 # mediawiki/extensions/Popups
 

docs/change_listener.md

@@ -21,7 +21,7 @@ creators](http://redux.js.org/docs/api/bindActionCreators.html), i.e.
 ```javascript
 mw.popups.changeListeners.foo = function ( boundActions ) {
   var $link = $( '<a>' )
-    .attr( 'href': '#' )
+    .attr( 'href', '#' )
     .click( boundActions.showSettings );
 
   return function ( prevState, state ) {

docs/instrumentation.md

@@ -17,7 +17,7 @@ Since the event data varies with the value of the `action` property, events are
 
 When enqueuing and logging an event, data flows between the reducer and the change listener as follows:
 
-1. The state is initialized to `null`..
+1. The state is initialized to `null`.
 2. An event is enqueued by the reducer as a result of an action.
 3. The change listener sees that the state tree has changed and logs the queued event via `mw.eventLog.Schema#log`.
 4. The change listener dispatches the `EVENT_LOGGED` action.