Fix paper mistakes

[a-vanderheiden]

• “mitigate future erosion” should probably be “mitigates future erosion” for subject–verb agreement in the Summary section.
• “end users can extend ScrollStats by supplying their own list of classier functions” appears to contain a typo; “classier” should likely be “classifier”.
• “Aggregate values represent the medain value” seems to have a typo

Fixed above mistakes found in the paper

Source