Update port description, add catch

Author: RichardLitt

README.md

@@ -20,7 +20,7 @@ $ npm install --save ipfs-api
 
 #### Running the daemon with the right port
 
-To interact with the API, you need to have a local daemon running (at the moment; we have plans to make it work independently). It needs to be open on the right port: `5001`. This is the default.
+To interact with the API, you need to have a local daemon running (at the moment; we have plans to make it work independently). It needs to be open on the right port. `5001` is the default, and is used in the examples below, but it can be set to whatever you need.
 
 ```sh
 # Show the ipfs config API port to check it is correct
@@ -94,6 +94,9 @@ ipfs.id()
   .then(function (id) {
     console.log('my id is: ', id)
   })
+  .catch(function(err) {
+  	console.log('Fail: ', err)
+  })
 ```
 
 This relies on a global `Promise` object. If you are in an environment where that is not