Update docs/howto_guides/replacing_asdfs.rst

Co-authored-by: Stuart Mumford <[email protected]>

docs/howto_guides/replacing_asdfs.rst

@@ -22,7 +22,7 @@ For example:
 where ``res`` is the result of a ``Fido`` search for some dataset you already have saved locally.
 
 You might also need to force a refresh of the sample data which is included with the Python tools.
-Again, we can use the `overwrite` keyword for this.
+Again, we can use the ``overwrite`` keyword for this.
 
 .. code-block:: python