Update docs/docs/usage/language-versions.md

Co-Authored-By: Nicolas Stucki <[email protected]>

Author: odersky

docs/docs/usage/language-versions.md

@@ -14,7 +14,7 @@ The default Scala language version currently supported by the Dotty compiler is
     - gives some additional warnings where the semantics has changed between Scala 2.13 and 3.0
     - in conjunction with `-rewrite`, offer code rewrites from Scala 2.13 to 3.0.
 
- - `3.1-migration: Same as `3.1` but with additional helpers to migrate from `3.0`. Similarly to the helpers available under `3.0-migration`, these include migration warnings and optional rewrites.
+ - `3.1-migration`: Same as `3.1` but with additional helpers to migrate from `3.0`. Similarly to the helpers available under `3.0-migration`, these include migration warnings and optional rewrites.
 
 There are two ways to specify a language version.