Refs #11418. Fixing two minor doc issues.

Code/Mantid/docs/source/algorithms/PoldiCreatePeaksFromFile-v1.rst

@@ -21,7 +21,7 @@ PoldiCreatePeaksFromFile reads a text file which contains one or more crystal st
 analysis requires information mainly about the lattice and the symmetry, the format is very simple. The following
 block shows how such a file would look when there are two compounds:
 
-.. code-block::
+.. code-block:: none
 
     # The name may contain letters, numbers and _
     Iron_FCC {
@@ -82,4 +82,6 @@ The script produces a WorkspaceGroup which contains a table with reflections for
 
 .. testcleanup::
 
-    DeleteWorkspace('compounds')
+    DeleteWorkspace('compounds')
\ No newline at end of file
+
+.. categories::