v2.1.0

This release adds support for cache persistence which is bringing us one step closer to
full offline-support, which we hope to bring you soon.

It also allows wonka@^4.0.0 as a dependency to be compatible with [email protected]. It also fixes a couple of issues in our
new populateExchange.

• Refactor internal store code and simplify Store (see #134)
• ✨ Implement store persistence support (see #137)
• ✨ Apply GC to store persistence (see #138)
• Remove unused case where scalars are written from an API when links are expected (see #142)
• ⚠️ Add support for resolvers causing cache misses (see #143)
• ⚠️ Fix nested types (e.g. [Item!]!) in populateExchange (see #150)
• Fix duplicate fragments in populateExchange output (see #151)
• Allow wonka@^3.2.1||^4.0.0 to be used (see #153)