Update define-plugin.md

[foreheadSniffer]

describe your changes...

• Read and sign the CLA. PRs that haven't signed it won't be accepted.
• Make sure your PR complies with the writer's guide.
• Review the diff carefully as sometimes this can reveal issues.
• Remove these instructions from your PR as they are for your eyes only.

[jsf-clabot]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

[nveenjain]

@foreheadSniffer , Thanks for the PR, but could you please sign the CLA first, so that we can proceed with this PR.

[dhruvdutt]

@foreheadSniffer Any update on this? :)

[montogeek]

Thanks!