Add documentation for migrating metadata between instances

[shmsr]

CATEGORY

Choose one

• [ ] Bug Fix
• [ ] Enhancement (new features, refinement)
• [ ] Refactor
• [ ] Add tests
• [ ] Build / Development Environment
• [x] Documentation

SUMMARY

Relives one from importing dashboards from *.json and also from manually setting up publisher/ subscription configurations for every applicable chart.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TEST PLAN

ADDITIONAL INFORMATION

• [ ] Has associated issue:
• [ ] Changes UI
• [ ] Requires DB Migration.
• [ ] Confirm DB Migration upgrade and downgrade tested.
• [ ] Introduces new feature or API
• [ ] Removes existing feature or API

REVIEWERS