Fail to run html

[Reueben Limbu]

...problem
404 not found page displayed, localhost:8080

launch.json file look like this,
{
"version": "0.2.0",
"configurations": [
{
"type": "chrome",
"request": "launch",
"name": "Launch Chrome against localhost",
"url": "http://localhost:8080",
"webRoot": "${workspaceFolder}"
}
]
} ...