Check low-level documentation to be sure that is up to date

[feliperuhland]

Low-level API

• Configs
• Containers Fix containers low-level documentation examples #2801
• Images Fix images low-level documentation examples #2799
• Building images
• Networks Fix network low-level documentation examples #2805
• Volumes Fix volumes low-level documentation examples #2806
• Executing commands in containers
• Swarms Fix swarm low-level documentation examples #2810
• Services
• Plugins
• Secrets
• The Docker daemon Fix daemon low-level documentation examples #2812
• Configuration types

[feliperuhland]

@ulyssessouza could you assign that issue to me?