Update the tag of the example image. (#4694)
Update the tag of the example image. (#4694)

Change the tag form "part1" to "part2" to match the tutorial progression.
shin-/docker.github.io,JimGalasyn/docker.github.io,londoncalling/docker.github.io,JimGalasyn/docker.github.io,johnstep/docker.github.io,shubheksha/docker.github.io,shin-/docker.github.io,shubheksha/docker.github.io,docker/docker.github.io,JimGalasyn/docker.github.io,londoncalling/docker.github.io,johnstep/docker.github.io,anweiss/docker.github.io,shubheksha/docker.github.io,shin-/docker.github.io,johnstep/docker.github.io,londoncalling/docker.github.io,shin-/docker.github.io,anweiss/docker.github.io,anweiss/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,anweiss/docker.github.io,thaJeztah/docker.github.io,shubheksha/docker.github.io,londoncalling/docker.github.io,JimGalasyn/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,shin-/docker.github.io,docker/docker.github.io,johnstep/docker.github.io,anweiss/docker.github.io,johnstep/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,shubheksha/docker.github.io,JimGalasyn/docker.github.io