Nvim: add missing files for various plugins

.config/nvim/lua/plugins/peek.lua

@@ -1,6 +1,7 @@
 return {
   'toppair/peek.nvim',
   build = 'deno task --quiet build:fast',
+  ft = { "markdown", "md" },
   config = function()
     -- default config:
     require('peek').setup({