allow config lsp with function

lua/navigator/lspclient/clients.lua

@@ -442,7 +442,13 @@ local function lsp_startup(ft, retry, user_lsp_opts)
         goto continue
       end
     end
-    if user_lsp_opts[lspclient] ~= nil and user_lsp_opts[lspclient].filetypes ~= nil then
+
+    -- for lazy loading
+    -- e.g. {lsp={tsserver=function() if tsver>'1.17' then return {xxx} else return {xxx} end}}
+    if type(user_lsp_opts[lspclient]) == 'function' then
+      user_lsp_opts[lspclient] = user_lsp_opts[lspclient]()
+      trace('loading from func:', user_lsp_opts[lspclient])
+    elseif user_lsp_opts[lspclient] ~= nil and user_lsp_opts[lspclient].filetypes ~= nil then
       if not vim.tbl_contains(user_lsp_opts[lspclient].filetypes, ft) then
         trace('ft', ft, 'disabled for', lspclient)
         goto continue