t.rast.accumulate: explain method parameter (todo: make identical to r.series.accumulate)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@65920 15284696-431f-4ddb-bdfa-cd5b030d7da7

temporal/t.rast.accumulate/t.rast.accumulate.py

@@ -119,7 +119,8 @@
 #%option
 #% key: method
 #% type: string
-#% description: This method will be applied to compute the accumulative values from the input maps in a single granule
+#% label: This method will be applied to compute the accumulative values from the input maps in a single granule
+#% description: Growing Degree Days or Winkler indices; Mean: sum(input maps)/(number of input maps); Biologically Effective Degree Days; Huglin Heliothermal index
 #% options: mean,gdd,bedd,huglin
 #% answer: mean
 #% required: no