enhance: improved notices.show_notices (#70)

- Prefer use of lua functions instead of vim.cmd
 - Added buffer and window options
 - Moved from append to appendbufline

lua/lualine/utils/notices.lua

@@ -36,12 +36,22 @@ function M.notice_message_startup()
 end
 
 function M.show_notices()
-  vim.cmd [[
-  :silent! new
-  :silent! setl ft=markdown bt=nofile nobuflisted bh=wipe
-  :silent! nnoremap <silent><buffer> q <cmd>bd<cr>
-  :silent! normal ggdG
-  ]]
+  vim.cmd('silent! keepalt split')
+
+  local winid = vim.fn.win_getid()
+  local bufnr = vim.api.nvim_create_buf(false, true)
+  vim.api.nvim_win_set_buf(winid, bufnr)
+
+  vim.wo[winid].winfixheight   = true
+  vim.wo[winid].winfixwidth    = true
+  vim.wo[winid].number         = false
+  vim.wo[winid].foldcolumn     = '0'
+  vim.wo[winid].relativenumber = false
+  vim.wo[winid].signcolumn     = 'no'
+  vim.bo[bufnr].filetype       = 'markdown'
+
+  vim.api.nvim_buf_set_keymap(bufnr, 'n', 'q', '<Cmd>bd<CR>', { noremap = true, silent = true })
+
   local ok, _ = pcall(vim.api.nvim_buf_set_name, 0, 'Lualine Notices')
   if not ok then
     vim.notify('Lualine Notices is already open in another window', vim.log.levels.ERROR, {})
@@ -50,9 +60,12 @@ function M.show_notices()
   end
   local notice = vim.tbl_flatten(persistent_notices)
   notice = vim.list_extend(notice, vim.tbl_flatten(notices))
-  vim.fn.append(0, notice)
-  vim.api.nvim_win_set_cursor(0, { 1, 0 })
-  vim.bo.modifiable=false
+  vim.fn.appendbufline(bufnr, 0, notice)
+
+  vim.fn.deletebufline(bufnr, #notice, vim.fn.line('$'))
+  vim.api.nvim_win_set_cursor(winid, { 1, 0 })
+  vim.bo[bufnr].modified  = false
+  vim.bo[bufnr].modifiable  = false
 end
 
 function M.clear_notices()