My Visual Studio Code Extension does not show up in the sidebar

Have somebody an idea why my extension is not showing up in the sidebar ín Visual Studio Code? If I bring the extension in my extension folder, the extension works but do not show up in the sidebar.

Repo: https://github.com/peni4142/work-as-two

package.json:

{
    "name": "work-as-two",
    "displayName": "work-as-two",
    "author": {
        "name": "peni4142"
    },
    "description": "Opens the associated file for simultaneous work on two files.",
    "version": "0.1.0",
    "icon": "work-as-two.jpg",
    "license": "GPL-3.0-or-later",
    "keywords": [
        "tdd",
        "testdriven",
        "web",
        "html",
        "css"
    ],
    "repository": {
        "url": "https://github.com/peni4142/work-as-two"
    },
    "publishConfig": {
        "registry": "https://npm.pkg.github.com/"
    },
    "engines": {
        "vscode": "^1.41.0"
    },
    "categories": [
        "Other"
    ],
    "activationEvents": [
        "*"
    ],
    "main": "./dist/extension.js",
    "contributes": {},
    "scripts": {
        "vscode:prepublish": "npm run build",
        "compile": "webpack --mode development",
        "watch": "webpack --mode development -w",
        "pretestVscode": "npm run compile",
        "test": "mocha -r ts-node/register src/**/*.test.ts -u tdd",
        "testVscode": "node ./out/test/runTest.js",
        "build": "webpack --mode production"
    },
    "devDependencies": {
        "@types/glob": "^7.1.1",
        "@types/mocha": "^5.2.7",
        "@types/node": "^12.11.7",
        "@types/vscode": "^1.41.0",
        "glob": "^7.1.5",
        "ts-loader": "^6.2.1",
        "ts-node": "^8.6.2",
        "tslint": "^5.20.0",
        "typescript": "^3.6.4",
        "vscode-test": "^1.2.2",
        "webpack": "^4.41.5",
        "webpack-cli": "^3.3.10"
    }
}