Changelog for covenant-1.3.0

Changelog for `covenant`

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog.

Zipper for the ASG in Covenant.Zipper
topLevelId function in Covenant.ASG
Changed type name representation of base functors from a _F suffix to a # prefix. For example, the base functor for List is now named #List instead of List_F.
Changed base functor lookup machinery / representation to not require raw TyName text manipulation
Provided helper function for safe construction of base functor names from the parent TyName
ASG now exposes a read-only pattern synonym
ValNodeInfo's pattern for App now exposes type applications as well
JSON serialization and deserialization support for ASGs with type declarations

Helper function for safely retrieving an in-scope type variable when constructing the ASG
Removed Return nodes, associated pattern synonyms, and the ret ASGBuilder function
Reworked the renamer to be context sensitive
Added new error types for un-renaming
Modified ASG helper functions and updated tests to conform with renamer rework
Added support for introduction forms (ValNode stuff, ASG helper function, tests)
Added support for catamorphism elimination forms
Added support for pattern matching elimination form

Representation of datatype declarations and datatype types
Generators for various flavors of data declaration and value type
A "kind checker" which serves as a basic sanity check on datatype declarations ingested by the pipeline
Base functor transformation machinery
Tests for the base functor transformation
Misc internal helpers to support the above functionality
Ledger type definitions for use in the ASG
Support for primops over data types
Support for arity-six primops in the ASG

Initial version