feat: nixvim config

currently only for dnsc-air. can simply be imported in other hosts

modules/nixvim/lsp.nix

@@ -0,0 +1,67 @@
+{ pkgs, ... }:
+
+{
+  plugins.lspconfig.enable = true;
+
+  lsp = {
+    enable = true;
+
+    servers = {
+      lua_ls = {
+        enable = true;
+        package = pkgs.lua-language-server;
+        packageFallback = true;
+      };
+      nil_ls = {
+        enable = true;
+        package = pkgs.nil;
+        packageFallback = true;
+      };
+      ts_ls = {
+        enable = true;
+        package = pkgs.typescript-language-server;
+        packageFallback = true;
+      };
+      jsonls = {
+        enable = true;
+        package = pkgs.vscode-langservers-extracted;
+        packageFallback = true;
+      };
+      astro = {
+        enable = true;
+        package = pkgs.astro-language-server;
+        packageFallback = true;
+      };
+      eslint = {
+        enable = true;
+        package = pkgs.vscode-langservers-extracted;
+        packageFallback = true;
+      };
+      biome = {
+        enable = true;
+        package = pkgs.biome;
+        packageFallback = true;
+      };
+    };
+
+    keymaps = [
+      {
+        key = "<leader>ca";
+        lspBufAction = "code_action";
+      }
+      {
+        key = "<leader>e";
+        action = "<cmd>lua vim.diagnostic.open_float()<cr>";
+      }
+    ];
+  };
+
+  # Define diagnostic appearance
+  diagnostic.settings = {
+    virtual_text = false;
+    signs = true;
+    underline = true;
+    update_in_insert = false;
+    severity_sort = false;
+  };
+}