Index through chat messages and commands using the arrow keys.

[jxhug]

Description

You can now index through chat messages and commands using the arrow keys. Fixes #160.

Type of change

Please delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation comments
• [x] My changes generate no new warnings

[stackotter]

It works 🎉