Force line breaking to fix the rendering error on long code.

Author: DingkunLiu

doc/python_reference.rst

@@ -2,6 +2,10 @@
 
 .. _api_reference:
 
+.. |br| raw:: html
+
+   <br />
+
 ====================
 Python API Reference
 ====================

surfer/viz.py

@@ -1350,8 +1350,8 @@ def add_label(self, label, color=None, alpha=1, scalar_thresh=None,
             If a label is specified as name, subdir can be used to indicate
             that the label file is in a sub-directory of the subject's
             label directory rather than in the label directory itself (e.g.
-            for ``$SUBJECTS_DIR/$SUBJECT/label/aparc/lh.cuneus.label``
-            ``brain.add_label('cuneus', subdir='aparc')``).
+            for |br| ``$SUBJECTS_DIR/$SUBJECT/label/aparc/lh.cuneus.label``
+            |br| ``brain.add_label('cuneus', subdir='aparc')``).
         **kwargs : additional keyword arguments
             These are passed to the underlying
             `mayavi.mlab.pipeline.surface` call.