Add the installation guide with aqua to the document

[suzuki-shunsuke]

Hi, thank you for your great project!

We suggest to add the installation guide with aqua to the document.
aqua is a declarative CLI Version Manager.
You can install this tool with aqua.

aqua init # Create aqua.yaml
aqua g -i k1LoW/octocov # Add this tool to aqua.yaml
aqua i # Install tools

For the detail of aqua, please see the official document.

We expect you can just copy and paste the following guide to your document.

---

Install with aqua

You can install this tool with aqua.

aqua g -i k1LoW/octocov # Add k1LoW/octocov to aqua.yaml

---

Thank you.

This issue was created automatically by script. For the detail, please see here.