docs: add stackoverflow tag

Author: jimthedev

README.md

@@ -2,7 +2,7 @@
 When you commit with Commitizen, you'll be prompted to fill out any required commit fields at commit time. No more waiting until later for a git commit hook to run and reject your commit (though [that](https://github.com/kentcdodds/validate-commit-msg) can still be helpful). No more digging through [CONTRIBUTING.md](CONTRIBUTING.md) to find what the preferred format is. Get instant feedback on your commit message formatting and be prompted for required fields.
 
 [![Backers on Open Collective](https://opencollective.com/commitizen/backers/badge.svg)](#backers) [![Sponsors on Open Collective](https://opencollective.com/commitizen/sponsors/badge.svg)](#sponsors) [![travis.ci](https://img.shields.io/travis/commitizen/cz-cli.svg?style=flat-square&branch=master)](https://travis-ci.org/commitizen/cz-cli) [![Azure Build Status](https://dev.azure.com/commitizen/cz-cli/_apis/build/status/commitizen.cz-cli?branchName=master)](https://dev.azure.com/commitizen/cz-cli/_build/latest?definitionId=2) 
- [![codecov.io](https://img.shields.io/codecov/c/github/commitizen/cz-cli.svg?style=flat-square)](https://codecov.io/github/commitizen/cz-cli?branch=master) [![npm monthly downloads](https://img.shields.io/npm/dm/commitizen.svg?style=flat-square)](https://www.npmjs.com/package/commitizen) [![current version](https://img.shields.io/npm/v/commitizen.svg?style=flat-square)](https://www.npmjs.com/package/commitizen) [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg?style=flat-square)](https://github.com/semantic-release/semantic-release)
+ [![codecov.io](https://img.shields.io/codecov/c/github/commitizen/cz-cli.svg?style=flat-square)](https://codecov.io/github/commitizen/cz-cli?branch=master) [![npm monthly downloads](https://img.shields.io/npm/dm/commitizen.svg?style=flat-square)](https://www.npmjs.com/package/commitizen) [![current version](https://img.shields.io/npm/v/commitizen.svg?style=flat-square)](https://www.npmjs.com/package/commitizen) [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg?style=flat-square)](https://github.com/semantic-release/semantic-release) [![commitizen on stackoverflow](https://img.shields.io/badge/stackoverflow-community-orange.svg?longCache=true&style=flat-square&logo=stackoverflow)](https://stackoverflow.com/tags/commitizen)
 
 #### Installing the command line tool
 Installation is as simple as running the following command (if you see `EACCES` error, reading [fixing npm permissions](https://docs.npmjs.com/getting-started/fixing-npm-permissions) may help):