Lower bash support from 3.2 to 3.0

[Chemaclass]

📚 Description

Closes: https://github.com/TypedDevs/bashunit/issues/468 by @akinomyoga

Right now, the min supported version is bash 3.2

🔖 Changes

• Allow bash 3.0 and above

✅ To-do list

• [x] I updated the CHANGELOG.md to reflect the new feature or fix
• [x] I updated the documentation to reflect the changes