Add Appnotes describing external references and using OpenTimelineIO

[samdbmg]

Details

• Adds an appnote with suggested reference formats for referring to TAMS content in other systems
• Adds an appnote describing how to use TAMS references in OpenTimelineIO compositions

Jira Issue (if relevant)

Jira URL: https://jira.dev.bbc.co.uk/browse/CLOUDFIT-3522

Related PRs

Builds on and implements parts of #90

Submitter PR Checks

(tick as appropriate)

• PR completes task/fixes bug
• API version has been incremented if necessary
• ADR status has been updated, and ADR implementation has been recorded
• Documentation updated (README, etc.)
• PR added to Jira Issue (if relevant)
• Follow-up stories added to Jira

Reviewer PR Checks

(tick as appropriate)

• PR completes task/fixes bug
• Design makes sense, and fits with our current code base
• Code is easy to follow
• PR size is sensible
• Commit history is sensible and tidy

Info on PRs

The checks above are guidelines. They don't all have to be ticked, but they should all have been considered.