Merge pull request #824 from cmu-delphi/survey/wave13-correction

Correct Wave 13 overlap description

Author: krivard

docs/symptom-survey/coding.md

@@ -956,8 +956,8 @@ is finalized.
 ## Wave 13
 
 Wave 13 was deployed on January 30, 2022. For the following two weeks, about 15%
-of respondents (selected at random) received Wave 13 and the remainder received
-Wave 12, allowing for comparisons of responses between the two waves. Wave 13 is
+of respondents (selected at random) received Wave 12 and the remainder received
+Wave 13, allowing for comparisons of responses between the two waves. Wave 13 is
 available in English and the languages introduced in Wave 3.
 
 There are two objectives of this revision. First, we modified the COVID-19