Update docstrings and API docs for Doc class

spacy/tokens/doc.pyx

@@ -267,7 +267,10 @@ cdef class Doc:
             self._vector = value
 
     property vector_norm:
-        # TODO: docstrings / docs
+        """The L2 norm of the document's vector representation.
+
+        RETURNS (float): The L2 norm of the vector representation.
+        """
         def __get__(self):
             if 'vector_norm' in self.user_hooks:
                 return self.user_hooks['vector_norm'](self)

website/docs/api/doc.jade

@@ -501,6 +501,19 @@ p
         +cell #[code numpy.ndarray[ndim=1, dtype='float32']]
         +cell A 1D numpy array representing the document's semantics.
 
++h(2, "vector_norm") Doc.vector_norm
+    +tag property
+    +tag requires model
+
+p
+    |  The L2 norm of the document's vector representation.
+
++table(["Name", "Type", "Description"])
+    +footrow
+        +cell return
+        +cell float
+        +cell The L2 norm of the vector representation.
+
 +h(2, "attributes") Attributes
 
 +table(["Name", "Type", "Description"])
@@ -514,6 +527,11 @@ p
         +cell #[code Vocab]
         +cell The store of lexical types.
 
+    +row
+        +cell #[code tensor]
+        +cell object
+        +cell Container for dense vector representations.
+
     +row
         +cell #[code user_data]
         +cell -