testing/mdbook: upgrade to 0.4.11

 - Add shell completions.
8 jobs for !23652 with mdbook in 31 minutes (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Lint
passed #448146
docker-alpine x86_64
lint

00:00:18

 
  Build
passed #448151
docker-alpine ci-build aarch64
build-aarch64

00:20:26

passed #448153
docker-alpine ci-build armhf
build-armhf

00:30:41

passed #448152
docker-alpine ci-build armv7
build-armv7

00:17:45

passed #448150
docker-alpine ci-build ppc64le
build-ppc64le

00:11:08

passed #448149
docker-alpine ci-build s390x
build-s390x

00:00:23

passed #448148
docker-alpine ci-build x86
build-x86

00:07:18

passed #448147
docker-alpine ci-build x86_64
build-x86_64

00:05:21