Change kernel to be accept a list of kernels

List of kernel paths are formatted into JUPYTER_PATH environment
variable

jupyter.nix

@@ -1,20 +1,25 @@
 {
-  pkgs,
-  kernel,
-  python ? pkgs.python3,
+  mkShellNoCC,
+  python3,
+  kernels ? [],
+  extraPackages ? (ps: []),
 }:
-pkgs.mkShellNoCC {
+mkShellNoCC {
   nativeBuildInputs = [
-    (python.withPackages (ps:
-      with ps; [
-        jupyterlab
-        jupyterlab-git
-        nbdime
-        nbconvert
-        (ps.callPackage ./catppuccin_jupyterlab {})
-      ]))
+    (python3.withPackages (ps:
+      with ps;
+        [
+          jupyterlab
+          jupyterlab-git
+          nbdime
+          nbconvert
+          python-lsp-server
+          (ps.callPackage ./catppuccin_jupyterlab {})
+        ]
+        ++ (extraPackages ps)))
   ];
-  shellHook = ''
-    export JUPYTER_PATH=${kernel}
-  '';
+  shellHook = with builtins; let
+    kernelString = foldl' (x: y: ":" + (toString y) + x) "" kernels;
+    pathString = substring 1 (stringLength kernelString) kernelString;
+  in "export JUPYTER_PATH=${pathString}";
 }