REQUEST: Create specs-entities-approvers group

[jsuereth]

We'd like to create a new group that can own Resource and Entity related specification changes going forward.

The group/team should be named specs-entities-approvers to match other spec-*-approvers groups.

This group would have approval rights in the open-telemetry/opentelemetry-specification repository and the following directories:

• specification/resource
• specification/entities

This group should have the following members:

• @jsuereth
• @dmitryax
• @dyladan
• @smith
• @tigrannajaryan
• @tedsuo

[trask]

I've sent https://github.com/open-telemetry/admin/pull/65 to create the team and give it write permission to the spec repo (which is needed so it can be added to CODEOWNERS).

Once that is merged, I will populate the team with the members above (we aren't managing team members via IaC yet),

[trask]

This is done now