feat(Man): port to Lua (#19912)

Co-authored-by: zeertzjq <zeertzjq@outlook.com>

runtime/plugin/man.lua

@@ -0,0 +1,34 @@
+if vim.g.loaded_man ~= nil then
+  return
+end
+vim.g.loaded_man = true
+
+vim.api.nvim_create_user_command('Man', function(params)
+  local man = require('man')
+  if params.bang then
+    man.init_pager()
+  else
+    local ok, err = pcall(man.open_page, params.count, params.smods, params.fargs)
+    if not ok then
+      vim.notify(man.errormsg or err, vim.log.levels.ERROR)
+    end
+  end
+end, {
+  bang = true,
+  bar = true,
+  addr = 'other',
+  nargs = '*',
+  complete = function(...)
+    return require('man').man_complete(...)
+  end,
+})
+
+local augroup = vim.api.nvim_create_augroup('man', {})
+
+vim.api.nvim_create_autocmd('BufReadCmd', {
+  group = augroup,
+  pattern = 'man://*',
+  callback = function(params)
+    require('man').read_page(vim.fn.matchstr(params.match, 'man://\\zs.*'))
+  end,
+})