Update README.md

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: mgeisler

README.md

@@ -55,7 +55,7 @@ The course is built using a few tools:
 
 In addition,
 [mdbook-linkcheck](https://github.com/Michael-F-Bryan/mdbook-linkcheck) checks
-the   internal   links.
+the internal links.
 
 First install Rust by following the instructions on https://rustup.rs/. Then
 clone this repository: