docs: provide information about usage

Close #19

Author: arsham

README.md

@@ -1,5 +1,48 @@
 # Gitrelease
 
 [![Continues Integration](https://github.com/arsham/gitrelease/actions/workflows/go.yml/badge.svg)](https://github.com/arsham/gitrelease/actions/workflows/go.yml)
+![License](https://img.shields.io/github/license/arsham/gitrelease)
 
-This program can set the release information based on all commits of a tag.
+This program can set the release information based on all commits of a tag. To
+see the example visit [Releases](https://github.com/arsham/gitrelease/releases)
+page.
+
+1. [Requirements](#requirements)
+2. [Installation](#installation)
+3. [Usage](#usage)
+4. [License](#license)
+
+## Requirements
+
+This program requires `Go >= v1.17`.
+
+## Installation
+
+To install:
+
+```bash
+go install github.com/arsham/gitrelease@latest
+```
+
+## Usage
+
+After you've made a tag, you can publish the current release documents by just
+running:
+
+```bash
+gitrelease
+```
+
+If you want to release an old tag:
+
+```bash
+gitrelease -t v0.1.2
+```
+
+## License
+
+Licensed under the MIT License. Check the [LICENSE](./LICENSE) file for details.
+
+<!--
+vim: foldlevel=1
+-->