Model workflow: pass --disable-documentation to cabal haddock (#109)

Closes #107.

README.md

@@ -200,9 +200,16 @@ jobs:
         run: cabal check
 
       - name: Build documentation
-        run: cabal haddock all
+        run:
+          cabal haddock all --disable-documentation
+          # --disable-documentation disables building documentation for dependencies.
+          # The package's own documentation is still built,
+          # yet contains no links to the documentation of the dependencies.
 ```
 
+Alternatively, the two occurrences of `--disable-documentation` can be changed to `--enable-documentation`, for resolving the external references to the documentation of the dependencies.
+This will increase build times a bit, though.
+
 ## Inputs
 
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