docs(router): Fix typo of missing symbol

closes #2111

Author: trotyl

public/docs/ts/latest/guide/router.jade

@@ -1450,7 +1450,7 @@ h3#resolve-guard <i>Resolve</i>: pre-fetching component data
   If we were using a real world api, there may be some delay in when the data we want to display gets returned.
   We don't want to display a blank component until the data loads in this situation.
 
-  We'd like to pre-fetch data from the server so its ready the moment our route is activated.
+  We'd like to pre-fetch data from the server so it's ready the moment our route is activated.
   We'd also like to handle the situation where our data fails to load or some other error condition occurs.
   This would help us in our `Crisis Center` if we navigated to an `id` that doesn't return a record.
   We could send the user back to the `Crisis List` where we only show valid crisis centers.