Fetch data from renamed Knative GitHub Organization

[upodroid]

Hello

I'm the Knative Productivity Working Group Lead and we recently renamed one of our GitHub organizations from knative-sandbox to knative-extensions.

Please update the scripts that fetch data from GitHub to reference the new org.

https://github.com/cncf/devstats/blob/master/projects.yaml#L1696
https://github.com/knative-sandbox
https://github.com/knative-extensions
knative/community#169

@lukaszgryglicki

[lukaszgryglicki]

I will work on this on Monday.

[lukaszgryglicki]

On it. There will be more files to change in more repos - but I will handle all of this and update here. I will also figure out when this new org was added and will backfill the past data + regenerate TSDB/all stats.

[lukaszgryglicki]

This is done, closing.

[upodroid]

Thanks