plugins/neotest: move to by-name

plugins/by-name/neotest/default.nix

@@ -0,0 +1,40 @@
+{
+  lib,
+  ...
+}:
+with lib;
+let
+  inherit (lib.nixvim) mkRaw;
+in
+lib.nixvim.neovim-plugin.mkNeovimPlugin {
+  name = "neotest";
+
+  maintainers = [ maintainers.GaetanLepage ];
+
+  imports = [ ./adapters.nix ];
+
+  settingsOptions = (import ./options.nix { inherit lib; }) // {
+    adapters = mkOption {
+      type = with types; listOf strLua;
+      default = [ ];
+      apply = map mkRaw;
+      # NOTE: We hide this option from the documentation as users should use the top-level
+      # `adapters` option.
+      # They can still directly append raw lua code to this `settings.adapters` option.
+      # In this case, they are responsible for explicitly installing the manually added adapters.
+      visible = false;
+    };
+  };
+
+  settingsExample = {
+    quickfix.enabled = false;
+    output = {
+      enabled = true;
+      open_on_run = true;
+    };
+    output_panel = {
+      enabled = true;
+      open = "botright split | resize 15";
+    };
+  };
+}