nvim: split plugins into multiple files

.config/nvim/lua/plugins/markdown-preview.lua

@@ -0,0 +1,16 @@
+return {
+  -- preview for markdown filetypes
+  {
+    "iamcco/markdown-preview.nvim",
+    ft = { 'markdown' },
+    build = "cd app && yarn install",
+    config = function()
+      vim.cmd([[
+          function OpenMarkdownPreview (url)
+            execute "silent ! firefox --kiosk --new-window " . a:url
+          endfunction
+        ]])
+      vim.g.mkdp_browserfunc = "OpenMarkdownPreview"
+    end
+  }
+}