You can add language-specific settings into the VS Code preferences file (opened with cmd+,), for example:

// Configure editor settings to be overridden for javascript and typescript language files.
"[javascript]": {
    "editor.insertSpaces": true,
    "editor.tabSize": 2
},
"[typescript]": {
    "editor.insertSpaces": true,
    "editor.tabSize": 2
},
"[typescriptreact]": {
    "editor.insertSpaces": true,
    "editor.tabSize": 2
},
// Configure editor settings to be overridden for [go] language files.
"[go]": {
    "editor.insertSpaces": false,
    "editor.tabSize": 8
}