Merge pull request #706 from nomeata/patch-1

Improve Haskell example

examples.md

@@ -168,7 +168,8 @@ We cache the elements of the Cabal store separately, as the entirety of `~/.caba
       ~/.cabal/packages
       ~/.cabal/store
       dist-newstyle
-    key: ${{ runner.os }}-${{ matrix.ghc }}
+    key: ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('**/*.cabal', '**/cabal.project', '**/cabal.project.freeze') }}
+    restore-keys: ${{ runner.os }}-${{ matrix.ghc }}-
 ```
 
 ## Java - Gradle