added zk and markdown

lua/plugins/zk.lua

@@ -0,0 +1,11 @@
+return {
+  'mickael-menu/zk-nvim',
+  config = function()
+    require('zk').setup({
+      picker = 'telescope',
+      config = {
+        on_attach = require('plugins.lspconfig').on_attach
+      }
+    })
+  end
+}