v0.13.68

Changes

Makes documentation anchors lowercase (#1791)
Anchors with uppercase letters found via

find docs/ -name '*.md' -exec grep -HEo '\(.*#[a-z]*[A-Z].*\)' {} \; | grep -v http

Followup on #1790

Docker image

Docker image is available in Zalando's Open Source registry:

docker run -it registry.opensource.zalan.do/teapot/skipper:v0.13.68 skipper --help
# arm64
docker run -it registry.opensource.zalan.do/teapot/skipper-arm64:v0.13.68 skipper --help
# arm v7 32bit
docker run -it registry.opensource.zalan.do/teapot/skipper-armv7:v0.13.68 skipper --help