docs: fix spelling in readme

Author: ethanholz

README.md

@@ -1,5 +1,5 @@
 # pdb2fasta-wasm-rust
 An example project that uses [knuckles-rs](https://github.com/ethanholz/knuckles-rs) to convert a PDB to a FASTA file based on the code found in this [pdb2fasta repo](https://github.com/kad-ecoli/pdb2fasta). This project uses `wasm-pack` and `wasm-bindgen` to generate WASM that is deployed to Cloudflare Pages.
 
-## Refernces
+## References
 - [https://github.com/kad-ecoli/pdb2fasta](https://github.com/kad-ecoli/pdb2fasta)