Docs Update Request

[tjohander-splunk]

The link to the list of supported ARNs for the x86_64 layers is broken. Right now the link points to

https://github.com/signalfx/lambda-layer-versions/blob/master/splunk-apm/splunk-apm/splunk-apm.md

But should be

https://github.com/signalfx/lambda-layer-versions/blob/master/splunk-apm/splunk-apm.md