Add tip about using conda-forge channel to install deno

docs/installation.rst

@@ -50,22 +50,27 @@ We can accomplish this using the following command:
 
     $ mamba install deno
 
-The new schema-based ``bids-validator`` doesn't need to be installed 
+.. tip::
+
+    If your mamba installation is not configured to use the conda-forge channel,
+    add ``-c conda-forge`` to the ``mamba install`` command.
+
+The new schema-based ``bids-validator`` doesn't need to be installed
 and will be implemented automatically when `cubids validate` is called
 
 .. dropdown:: If there is no Internet connection on compute nodes
 
-    If your HPC doesn't allow internet access on its compute nodes, it won't be able to run the online 
-    version of the BIDS validator. In that scenario, you need to install the BIDS validator on your HPC 
-    and then point to the installed version in your cubids validate calls. 
-    To do that, you should run one of these commands below, after installing deno, that downloads the latest version 
-    of the bids-validator in your virtual environment either by installing a lightscript version 
+    If your HPC doesn't allow internet access on its compute nodes, it won't be able to run the online
+    version of the BIDS validator. In that scenario, you need to install the BIDS validator on your HPC
+    and then point to the installed version in your cubids validate calls.
+    To do that, you should run one of these commands below, after installing deno, that downloads the latest version
+    of the bids-validator in your virtual environment either by installing a lightscript version
     (into ``$HOME/.deno/bin``) or by compiling, respectively:
 
     ..  code-block:: console
 
         $ deno install -ERN -g -n bids-validator jsr:@bids/validator
-    
+
     or:
 
     ..  code-block:: console