Create devcontainer.json

[mattsh247]

Timing

Description

Related DIP issue

Checklist

• [ ] Correct markdown (e.g. headers with ##, header surrounded by ---)
• [ ] syntax check
• [ ] filename is DIP-X.md (with X being the correct DIP number)
• [ ] header contains (in this order)
  • [ ] DIP
  • [ ] Title
  • [ ] Status
  • [ ] Themes
  • [ ] Tags
  • [ ] Authors
  • [ ] Resources Required (optional)
  • [ ] Discussion (with link to devcon forum)
  • [ ] Created (in the format year-month-day e.g 2020-4-20)
• [ ] contains these sections:
  • [ ] Abstract
  • [ ] Rationale
  • [ ] Implementation
  • [ ] Operational Requirements & Ownership
• [ ] PR title prefixed with DIP-X