Old download location for lightning.json

[dveeden]

Error Report

The lightning.json that is references is pointing to the https://github.com/pingcap/tidb-ansible repo that has been archived.

Looks like this was missed when #8816 was fixed due to this using the githubusercontent.com domain instead of github.com

1. What is the URL/path of the document related to this issue?

https://docs.pingcap.com/tidb/stable/monitor-tidb-lightning

2. How would you like to improve it?

Switch from:

• https://raw.githubusercontent.com/pingcap/tidb-ansible/master/scripts/lightning.json

To:

• https://raw.githubusercontent.com/pingcap/tidb/master/br/metrics/grafana/lightning.json

Might be good to review and refresh the complete page as well.