docs: add AffineUnit

MilesCranmer · MilesCranmer · commit 24a0c46df4fb · 2025-03-16T14:39:22.000+01:00
diff --git a/docs/src/units.md b/docs/src/units.md
@@ -64,6 +64,7 @@ Note there are some subtleties about working with these:
 ```@docs
 @ua_str
 aff_uparse
+DynamicQuantities.AffineUnit
 ```
 
 Currently, the only supported affine units are:
