Write initial settings to settings.json - visual-studio-code

Question

I am looking for a way to write initial settings to settings.json for when my extension is installed.
I found WorkspaceConfiguration API, but that seems to retrieving/updating values at runtime.
I'm looking to get my settings + comments into the default settings file
e.g. How TSLint does it:

Answer 1

I hope I get your question correctly: I assume you mean the User Settings settings.json you can get via File>Preferences>User Settings.
If you know that TSLint does it, you can go to your extensions folder (windows: $USERFOLDER/.vscode/extensions), pick the extension (in my case it was the folder "eg2.tslint-0.6.7") and peek the files.
...
"contributes": {
"configuration": {
"type": "object",
"title": "TSLint",
"properties": {
"tslint.enable": {
"type": "boolean",
"default": true,
"description": "Control whether tslint is enabled for TypeScript files or not."
},
"tslint.rulesDirectory": {
"type": [
"string",
"array"
],
"items": {
"type": "string"
},
"description": "An additional rules directory",
"default": ""
},
"tslint.validateWithDefaultConfig": {
"type": "boolean",
"description": "Validate a file when there is only a default tslint configuration is found",
"default": false
},
"tslint.configFile": {
"type": "string",
"description": "The path to the rules configuration file",
"default": ""
},
"tslint.ignoreDefinitionFiles": {
"type": "boolean",
"default": true,
"description": "Control if TypeScript definition files should be ignored"
},
"tslint.exclude": {
"type": [
"string",
"array"
],
"items": {
"type": "string"
},
"description": "Configure glob patterns of file paths to exclude from linting"
},
"tslint.run": {
"type": "string",
"enum": [
"onSave",
"onType"
],
"default": "onType",
"description": "Run the linter on save (onSave) or on type (onType)"
},
"tslint.nodePath": {
"type": "string",
"default": "",
"description": "A path added to NODE_PATH when resolving the tslint module."
},
"tslint.autoFixOnSave": {
"type": "boolean",
"default": false,
"description": "Turns auto fix on save on or off."
}
}
}
...
Hope this helps