fixes build status shield + adds coverage shield (#55)

README.md

@@ -1,9 +1,10 @@
 # jsonptr - JSON Pointers for Rust
 
-[<img alt="github" src="https://img.shields.io/badge/github-chanced/jsonptr-8da0cb?style=for-the-badge&labelColor=777&logo=github" height="21">](https://github.com/chanced/jsonptr)
+[<img alt="github" src="https://img.shields.io/badge/github-chanced/jsonptr-62D1FC?style=for-the-badge&labelColor=777&logo=github" height="21">](https://github.com/chanced/jsonptr)
 [<img alt="crates.io" src="https://img.shields.io/crates/v/jsonptr.svg?style=for-the-badge&color=fc8d62&logo=rust" height="21">](https://crates.io/crates/jsonptr)
 [<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-jsonptr-f0f0f0?style=for-the-badge&labelColor=777&logo=docs.rs" height="21">](https://docs.rs/jsonptr)
-[<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/chanced/jsonptr/rust.yml?branch=main&style=for-the-badge" height="21">](https://github.com/chanced/jsonptr/actions?query=branch%3Amain)
+[<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/chanced/jsonptr/test.yml?branch=main&style=for-the-badge" height="21">](https://github.com/chanced/jsonptr/actions?query=branch%3Amain)
+[<img alt="code coverage" src="https://img.shields.io/codecov/c/github/chanced/jsonptr?style=for-the-badge&color=CBB88D" height="21">](https://codecov.io/gh/chanced/jsonptr)
 
 Data structures and logic for resolving, assigning, and deleting by JSON Pointers ([RFC
 6901](https://datatracker.ietf.org/doc/html/rfc6901)).