New version: HerbCore v0.3.0

[JuliaRegistrator]

• Registering package: HerbCore
• Repository: https://github.com/Herb-AI/HerbCore.jl
• Created by: @ReubenJ
• Version: v0.3.0
• Commit: 6f0c831d0c1adc1483bb63598128a71f1af4fc07
• Reviewed by: @ReubenJ
• Reference: Herb-AI/HerbCore.jl@6f0c831#commitcomment-141365332
• Description: Core structures for Herb.jl
• Release notes:

## Added

- Code coverage for testing and reporting on Codecov
- `JuliaFormatter` support and CI workflow to enforce style on PRs
- CI workflow for checking that documentation builds
- `AbstractHole` and `AbstractUniformHole` types to support multiple (uniform) `Hole` types
- `AbstractConstraint` to support multiple constraint types
- `UniformHole` for holes where all rules in the domain have the same child types.
- `get_path(...)` to find a path between two `RuleNodes` in a tree if one exists
- `number_of_holes(...)`, `contains_nonuniform_hole(...)`, `get_children(...)`, `get_rule(...)`, `isuniform(...)`, `isfilled(...)`, `hasdynamicvalue(...)`, `have_same_shape(...)`

## Changed

- All methods that previously were typed for the concrete `Hole` now use the `AbstractHole`
- `RuleNode`-related methods (like `Base.isless`) updated to use `AbstractRuleNodes` to support a larger part of the type tree (`Hole`s, etc.) rather than only `RuleNode`s

[github-actions]

Your new version pull request met all of the guidelines for auto-merging and is scheduled to be merged in the next round.

---

If you want to prevent this pull request from being auto-merged, simply leave a comment. If you want to post a comment without blocking auto-merging, you must include the text [noblock] in your comment. You can edit blocking comments, adding [noblock] to them in order to unblock auto-merging.