Fix need tag formatting

armi/reactor/blueprints/assemblyBlueprint.py

@@ -123,7 +123,7 @@ class AssemblyBlueprint(yamlize.Object):
         assembly from within their blueprints file, including a name, flags, specifier
         for use in defining a core map, a list of blocks, a list of block heights,
         a list of axial mesh points in each block, a list of cross section identifiers
-        for each block, and material options (see :need:I_ARMI_MAT_USER_INPUT0).
+        for each block, and material options (see :need:`I_ARMI_MAT_USER_INPUT0`).
 
         Relies on the underlying infrastrature from the ``yamlize`` package for
         reading from text files, serialization, and internal storage of the data.