update CHANGELOG

Author: mbostock

CHANGELOG.md

@@ -79,7 +79,7 @@ Diverging color scales now also support transformations via four new scale types
 
 The new axis *line* option, which defaults to false, can be used to show a continuous line along the *x* or *y* axis to denote the extent. This is most useful when the opposite axis is ordinal and thus a rule cannot annotate a meaningful value such as zero; if the opposite axis is quantitative, a rule is generally preferred.
 
-<img width="640" alt="an empty plot showing a vertical line along the quantitative y-axis; the opposite x-axis is categorical" src="https://user-images.githubusercontent.com/230541/130158604-2b157912-e131-4736-bba0-0c7403818cf0.png">
+<img width="640" alt="an empty plot showing a vertical line along the quantitative y-axis; the opposite x-axis is categorical" src="https://user-images.githubusercontent.com/230541/130247773-d868d261-9744-4d57-855a-61a2a870655b.png">
 
 ```js
 Plot.plot({