Add some group parameter to convolutions. (#566)

* Add some group parameter to convolutions.

* Avoid some unnecessary groups checks.

* Move the tensor convolution bits.

* Properh handling of groups.

* Bump the crate version.

* And add a changelog.

candle-examples/examples/whisper/model.rs

@@ -308,10 +308,12 @@ impl AudioEncoder {
         let cfg1 = Conv1dConfig {
             padding: 1,
             stride: 1,
+            groups: 1,
         };
         let cfg2 = Conv1dConfig {
             padding: 1,
             stride: 2,
+            groups: 1,
         };
         let conv1 = conv1d(cfg.num_mel_bins, n_state, 3, cfg1, vb.pp("conv1"))?;
         let conv2 = conv1d(n_state, n_state, 3, cfg2, vb.pp("conv2"))?;