Update CHANGELOG

Author: mbostock

CHANGELOG.md

@@ -4,9 +4,9 @@
 
 *Not yet released. These are forthcoming changes in the main branch.*
 
-The vector mark now supports the **shape** constant option. The built-in shapes are *arrow* (default) and *spike*. A custom shape can also be implemented, returning the corresponding SVG path data for the desired shape. The new spike mark convenience constructor creates a vector suitable for spike maps. The vector mark also now supports an **r** constant option to further customize the shape.
+The [vector mark](./README.md#vector) now supports the **shape** constant option. The built-in shapes are *arrow* (default) and *spike*. A custom shape can also be implemented, returning the corresponding SVG path data for the desired shape. The new [spike convenience constructor](./README.md#plotspikedata-options) creates a vector suitable for spike maps. The vector mark also now supports an **r** constant option to further customize the shape.
 
-The new geoCentroid transform and centroid initializer transform compute the spherical and projected planar centroids of geometry, respectively.
+The new [geoCentroid transform](./README.md#plotgeocentroidoptions) and [centroid initializer](./README.md#plotcentroidoptions) compute the spherical and projected planar centroids of geometry, respectively.
 
 Diverging scales now correctly handle descending domains.