辗转反侧，弄了好久好久终于出山了

总结：跟vscode版本插件有关

老版本vscode DocsTool修改成godoc

新版本vscode 

1. go get golang.org/x/tools/gopls@latest

2. setting中

"go.useLanguageServer": true,
"[go]": {
    "editor.snippetSuggestions": "none",
    "editor.formatOnSave": true,
    "editor.codeActionsOnSave": {
        "source.organizeImports": true
    }
},
"gopls": {
    "usePlaceholders": true, // add parameter placeholders when completing a function
    "completionDocumentation": true // for documentation in completion items
},
"files.eol": "\n", // formatting only supports LF line endings