update CHANGELOG

Author: mbostock

CHANGELOG.md

@@ -4,12 +4,10 @@
 
 *Not yet released.* These notes are a work in progress.
 
-[breaking] Plot is now published as an ES module.
+[breaking] Plot is now published as an ES module and requires Node 12 or higher. For more on how to upgrade to ES modules, please read [Sindre Sorhus’s FAQ](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c).
 
 [breaking] Plot now depends on D3 7 or higher.
 
-[breaking] Plot now requires Node 12 or higher.
-
 ### Marks
 
 The [*marks* option](https://github.com/observablehq/plot/blob/main/README.md#mark-options) now accepts render functions, null, and undefined as shorthand mark definitions. Nullish marks produce no output and are useful for conditional display (equivalent to the empty array). Render functions are invoked when plotting and may return an SVG element to insert into the plot, such as a legend or annotation.