doc fix

Author: CarloLucibello

src/layers/conv.jl

@@ -637,12 +637,13 @@ Performs the operation
 \mathbf{x}_i' = \mathbf{x}_i + \sum_{j\in N(i)}\sigma(W_f \mathbf{z}_{ij} + \mathbf{b}_f)\, act(W_s \mathbf{z}_{ij} + \mathbf{b}_s)
 ```
 
-where ``z_ij``  is the node and edge features concatenation 
-``[\\mathbf{x}_i \\,\\|\\, \\mathbf{x}_j \\,\\|\\, \\mathbf{e}_{j\\to i}]`` 
-and ``\\sigma`` is the sigmoid function.
-The residual ``\\mathbf{x}_i`` is added only if `residual=true` and the output size is the same 
+where ``z_{ij}``  is the node and edge features concatenation 
+``[\mathbf{x}_i | \mathbf{x}_j | mathbf{e}_{j\to i}]`` 
+and ``\sigma`` is the sigmoid function.
+The residual ``\mathbf{x}_i`` is added only if `residual=true` and the output size is the same 
 as the input size.
 
+
 # Arguments
 
 - `nin`: The dimension of input node features.