Make minor fixes to openfaas workshop labs

[codegold79]

Description

Lab 7: fixed a typo by removing a back tick in a k8s command
Lab 11: updated link to Lab 5
Lab 5 (Japanese version): fixed broken image links

Motivation and Context

Changes will make labs more correct and easier to follow.

Fixes issues #161 #164 #163

• I have raised an issue to propose this change (required)

How Has This Been Tested?

I was able to click to images from my VS Code IDE, as well as go to the correct Lab 5 link.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[codegold79]

@alexellis This PR is ready for review.

[alexellis]

Thanks @codegold79 - this looks good.

[alexellis]

LGTM