Update CHANGELOG

Author: mbostock

CHANGELOG.md

@@ -8,7 +8,7 @@ Plot now supports [mark initializers](./README.md#initializers) via the **initia
 
 The new [hexbin transform](./README.md#hexbin) functions similarly to the bin transform, except it aggregates both *x* and *y* into hexagonal bins before reducing. The size of the hexagons can be specified with the **binWidth** option, which controls the width of the (pointy-topped) hexagons.
 
-<img src="./img/hexbin.png" width="640" alt="a chart showing the inverse relationship of fuel economy to engine displacement, and the positive correlation of engine displacement and weight; hexagonal bins of varying size represent the number of cars at each location, while color encodes the mean weight of nearby cars">
+[<img src="./img/hexbin.png" width="640" alt="a chart showing the inverse relationship of fuel economy to engine displacement, and the positive correlation of engine displacement and weight; hexagonal bins of varying size represent the number of cars at each location, while color encodes the mean weight of nearby cars">](https://observablehq.com/@observablehq/plot-hexbin)
 
 ```js
 Plot.plot({
@@ -29,7 +29,7 @@ Plot.plot({
 
 The new [dodge transform](./README.md#dodge) can be used to produce beeswarm plots. Given an *x* channel representing the desired horizontal position of circles, the dodgeY transform derives a new *y* (vertical position) channel such that the circles do not overlap; the dodgeX transform similarly derives a new *x* channel given a *y* channel. If an *r* channel is specified, the circles may have varying radius.
 
-<img src="./img/dodge.png" width="640" alt="a chart showing the monthly percent change in travel by U.S. county in March 2020 after the coronavirus outbreak; each county is represented as a circle with area proportional to its population, positioned according to the change in travel; most counties, and especially those with stay-at-home orders, show a significant reduction in travel">
+[<img src="./img/dodge.png" width="640" alt="a chart showing the monthly percent change in travel by U.S. county in March 2020 after the coronavirus outbreak; each county is represented as a circle with area proportional to its population, positioned according to the change in travel; most counties, and especially those with stay-at-home orders, show a significant reduction in travel">](https://observablehq.com/@observablehq/plot-dodge)
 
 ```js
 Plot.plot({