Spelling fixes in example notebook. Spotted by Jason Grout.

docs/examples/notebooks/01_notebook_introduction.ipynb

@@ -120,7 +120,7 b''
      "source": [
       "## User interface", 
       "", 
-      "When you start a new notebook server with `ipytyhon notebook`, your", 
+      "When you start a new notebook server with `ipython notebook`, your", 
       "browser should open into the *Dashboard*, a page listing all notebooks", 
       "available in the current directory as well as letting you create new", 
       "notebooks.  In this page, you can also drag and drop existing `.py` files", 
@@ -302,7 +302,7 b''
      "source": [
       "## The kernel's `raw_input` and `%debug`", 
       "", 
-      "The one feature the notebook currently doesn't support as a client is the ability to send data to the kerne's", 
+      "The one feature the notebook currently doesn't support as a client is the ability to send data to the kernel's", 
       "standard input socket.  That is, if the kernel requires information to be typed interactively by calling the", 
       "builtin `raw_input` function, the notebook will be blocked.  This happens for example if you run a script", 
       "that queries interactively for parameters, and very importantly, is how the interactive IPython debugger that ", 
@@ -418,4 +418,4 b''
    ]
   }
  ]
-}
  No newline at end of file
+}