Update irradiance.py

add date to sentence

Author: RDaxini

pvlib/irradiance.py

@@ -866,9 +866,9 @@ def reindl(surface_tilt, surface_azimuth, dhi, dni, ghi, dni_extra,
     Determine the diffuse irradiance from the sky on a tilted surface using
     the Reindl (1990) model.
 
-    The Reindl model [1]_ [2]_ determines the diffuse irradiance from the sky
-    (ground reflected irradiance is not included in this algorithm) on a
-    tilted surface using the surface tilt angle, surface azimuth angle,
+    The Reindl (1990) model [1]_ [2]_ determines the diffuse irradiance from
+    the sky (ground reflected irradiance is not included in this algorithm) on
+    a tilted surface using the surface tilt angle, surface azimuth angle,
     diffuse horizontal irradiance, direct normal irradiance, global
     horizontal irradiance, extraterrestrial normal irradiance, sun zenith
     angle, and sun azimuth angle.