feat(nvim): typst; tidy language specific configurations

.lazy.lua

@@ -1,3 +1,20 @@
+vim.lsp.config("nixd", {
+  settings = {
+    nixd = {
+      nixpkgs = {
+        expr = "import <nixpkgs> { }",
+      },
+      options = {
+        nixos = {
+          expr = '(builtins.getFlake ("git+file://" + toString ./.)).nixosConfigurations.'
+            .. vim.uv.os_gethostname()
+            .. ".options",
+        },
+      },
+    },
+  },
+})
+
 return {
   {
     "folke/lazydev.nvim",