Update name of model

models/csg-union-disjoint/README.md

@@ -1,10 +0,0 @@
-# Fornjot - Disjoint Union
-
-A model that demonstrates [constructive solid geometry](https://en.wikipedia.org/wiki/Constructive_solid_geometry) (CSG) functionality, specifically the union of two disjoint bodies.
-
-To display this model, run the following from the repository root:
-``` sh
-cargo run -- --model csg-union-disjoint
-```
-
-![Screenshot of the disjoint union model](csg-union-disjoint.png)

models/group/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name    = "csg-union-disjoint"
+name    = "group"
 version = "0.1.0"
 edition = "2021"
 

models/group/README.md

@@ -0,0 +1,10 @@
+# Fornjot - Group
+
+A model that demonstrates groups of two disjoint bodies.
+
+To display this model, run the following from the repository root:
+``` sh
+cargo run -- --model group
+```
+
+![Screenshot of the group model](group.png)