v0.3.0 - Named Sections and I/O

What's Changed

Major changes

• Named Sections and utilities for joining sections (parent/child logic) and I/O by @hdrake in #33
• Stabilize environment by replacing xgcm@master dependency with xgcm >= 0.9.0 by @hdrake in #33
• Point clone to MOM6-community by @hdrake in #32

Minor changes

• Updated Zenodo datasets by @hdrake in #30

Full Changelog: v0.2.2...v0.3.0