fix broken link on Delivery Plan page

location is:

devops-practices/continuous-planning/agile-development/delivery-plan.md

the 'Non-functional Features' link does not work.

[Non-functional Features](http://127.0.0.1:8000/devops-docs/devops-practices/continuous-planning/agile-development/continuous-planning/design-reviews/design-patterns/non-functional-requirements-capture-guide.md)