Update UnknownImport.md (#251)

Typo

Author: rszczers

errors/UnknownImport.md

@@ -19,6 +19,6 @@ This error occurs when trying to import a name which does not exist.
 ## Fix
 
 - Check spelling of any imported names.
-- Check dependencies to make sure you are using the correct versions. You can use [Pursuit](https//pursuit.purescript.org/) to check which package versions define the names you are trying to import.
+- Check dependencies to make sure you are using the correct versions. You can use [Pursuit](https://pursuit.purescript.org/) to check which package versions define the names you are trying to import.
 
 ## Notes