make a CN staking contract file public

[kaikookim]

Proposed changes

• make a CN staking contract file public

Types of changes

Please put an x in the boxes related to your change.

• Bugfix
• New feature or enhancement
• Others

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING GUIDELINES doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Related issues

• N/A

Further comments

• Additional documents(md file and comments) will be updated.

[CLAassistant]

All committers have signed the CLA.

[KimKyungup]

Thanks. :)