input2d: update readme

Author: OneAdder

README.md

@@ -29,12 +29,12 @@ Read the paper [here](https://arxiv.org/abs/1902.06714).
 
 | Layer type | Constructor name | Supported input layers | Rank of output array | Forward pass | Backward pass |
 |------------|------------------|------------------------|----------------------|--------------|---------------|
-| Input | `input` | n/a | 1, 3 | n/a | n/a |
-| Dense (fully-connected) | `dense` | `input1d`, `flatten` | 1 | ✅ | ✅ |
-| Convolutional (2-d) | `conv2d` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 3 | ✅ | ✅(*) |
-| Max-pooling (2-d) | `maxpool2d` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 3 | ✅ | ✅ |
-| Flatten | `flatten` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 1 | ✅ | ✅ |
-| Reshape (1-d to 3-d) | `reshape` | `input1d`, `dense`, `flatten` | 3 | ✅ | ✅ |
+| Input | `input` | n/a | 1, 2, 3              | n/a | n/a |
+| Dense (fully-connected) | `dense` | `input1d`, `flatten` | 1                    | ✅ | ✅ |
+| Convolutional (2-d) | `conv2d` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 3                    | ✅ | ✅(*) |
+| Max-pooling (2-d) | `maxpool2d` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 3                    | ✅ | ✅ |
+| Flatten | `flatten` | `input3d`, `conv2d`, `maxpool2d`, `reshape` | 1                    | ✅ | ✅ |
+| Reshape (1-d to 3-d) | `reshape` | `input1d`, `dense`, `flatten` | 3                    | ✅ | ✅ |
 
 (*) See Issue [#145](https://github.com/modern-fortran/neural-fortran/issues/145) regarding non-converging CNN training on the MNIST dataset.