chore(divan_compat): add bench_group to unsupported features

Author: GuillaumeLagrange

crates/divan_compat/README.md

@@ -77,5 +77,6 @@ Finished running 1 benchmark suite(s)
 
 ### Not supported:
 
-- `divan::bench(const = xxx)`: we do not support this feature yet, if you need it don't hesitate to create an issue.
-- `divan::bench(crate = xxx)`: due to how the compatibility layer works internally, we do not plan to support this feature.
+- [`divan::bench(crate = xxx)`](https://docs.rs/divan/latest/divan/attr.bench.html#crate): due to how the compatibility layer works internally, we do not plan to support this feature.
+- [`divan::bench(consts = xxx)`](https://docs.rs/divan/latest/divan/attr.bench.html#consts): we do not support this feature yet, if you need it don't hesitate to create an issue.
+- [`divan::bench_group`](https://docs.rs/divan/latest/divan/attr.bench_group.html): we do not support benchmark grouping this feature yet, if you need it don't hesitate to create an issue.