Update read me with usage guidance

[gracelungu]

Context

Guide the user through the usage of the bot on github

Task

• Inspect the modules to understand how the bot works
• Explain that the bot listens to issues creation, pr creation and pr review and pr review comments
• Once an issue is created the bot will pick it up and create a PR, same when a pr is created the bot will review it and as well when a comment review is added on a pr the bot can jump in comment or even add changes to the pr
• Also mention that these envs help configure the bot, and a label can be added in github when with label is yes to only trigger the bot for issues and prs with the label of the name of the bot: HANDLE_ISSUES=yes BOT_NAME=gitagentic WITH_LABEL=no HANDLE_PULL_REQUEST=yes

[gitagentic[bot]]

Thank you for opening this issue. I'm on it and will work on updating the README with usage guidance. I'll create a pull request shortly with the necessary changes.