title: Docstring format for input numpy arrays with mandatory datatype and dimensions
body: <p>For the sake of example, assume that I have a function that takes two numpy arrays as input parameters. The first array must be 2-dimensional and contain only floats. The second array must be 1-dimensional and contain only booleans.</p>
  
  <p>Thus far I haven't really been able to find an existing convention for specifying input array datatype and dimensions in the docstring. One possible format (taking numpy docstring conventions as a basis) that I thought of was this:</p>
  
  <pre><code>def example_function(arr1, arr2):
      """This is an example function.
  
      Parameters
      ----------
      arr1 : ndarray(dtype=float, ndim=2)
          Array containing some kind of data.
      arr2 : ndarray(dtype=bool, ndim=1)
          Array containing some kind of mask.
  
     """
  </code></pre>
  
  <p>Can this be considered a 'correct' docstring format? (i.e. does it not break any rules of existing docstring conventions?)</p>