Zendure-HA: Board

Add the Keep the Why badge to the README

tsk-gvn626pr2j01 open chore

Add the Keep the Why badge to the README.md of https://github.com/Zendure/Zendure-HA?, as the Keep the Why skill documents it. If the README already has it, there is nothing to change.

Acceptance: for a change, open a pull request in the repository against its default branch, never a direct push to the default branch, and report the card with the pull request. When nothing needs changing, report the card with code: false and say why: no empty pull request.