chore: disable linting autocmd for readonly buffers

Source: nvim-lua#1202

lua/kickstart/plugins/lint.lua

@@ -49,7 +49,12 @@ return {
       vim.api.nvim_create_autocmd({ 'BufEnter', 'BufWritePost', 'InsertLeave' }, {
         group = lint_augroup,
         callback = function()
-          lint.try_lint()
+          -- Only run the linter in buffers that you can modify in order to
+          -- avoid superfluous noise, notably within the handy LSP pop-ups that
+          -- describe the hovered symbol using Markdown.
+          if vim.opt_local.modifiable:get() then
+            lint.try_lint()
+          end
         end,
       })
     end,