Update README.md

Author: juliohm

README.md

@@ -42,7 +42,7 @@ pm = PeakOverThreshold(xs, 100.)
 
 For the block maxima model, the values `xs` need to represent a measurement over time,
 whereas the peak over threshold model does not assume any ordering in the data. Both
-models are lazy, and the maxima values are only returned via a call to `collect`.
+models are lazy, and the maxima are only returned via a `collect` call.
 
 ### Plotting