cabal check: Fix broken link to docs for description/synopsis

Cabal/src/Distribution/PackageDescription/Check/Warning.hs

@@ -926,7 +926,8 @@ ppExplanation ShortDesc =
     ++ "(e.g. 'cabal info', Haddock, Hackage) below the 'synopsis' which "
     ++ "serves as a headline. "
     ++ "Please refer to <https://cabal.readthedocs.io/en/stable/"
-    ++ "cabal-package.html#package-properties> for more details."
+    ++ "cabal-package-description-file.html#package-properties> "
+    ++ "for more details."
 ppExplanation (InvalidTestWith testedWithImpossibleRanges) =
   "Invalid 'tested-with' version range: "
     ++ commaSep (map prettyShow testedWithImpossibleRanges)

cabal-testsuite/PackageTests/Check/ConfiguredPackage/Fields/ShortDescription/cabal.out

@@ -1,3 +1,3 @@
 # cabal check
 These warnings will likely cause trouble when distributing the package:
-Warning: [short-description] The 'description' field should be longer than the 'synopsis' field. It's useful to provide an informative 'description' to allow Haskell programmers who have never heard about your package to understand the purpose of your package. The 'description' field content is typically shown by tooling (e.g. 'cabal info', Haddock, Hackage) below the 'synopsis' which serves as a headline. Please refer to <https://cabal.readthedocs.io/en/stable/cabal-package.html#package-properties> for more details.
+Warning: [short-description] The 'description' field should be longer than the 'synopsis' field. It's useful to provide an informative 'description' to allow Haskell programmers who have never heard about your package to understand the purpose of your package. The 'description' field content is typically shown by tooling (e.g. 'cabal info', Haddock, Hackage) below the 'synopsis' which serves as a headline. Please refer to <https://cabal.readthedocs.io/en/stable/cabal-package-description-file.html#package-properties> for more details.

cabal-testsuite/PackageTests/Check/IgnoreWarning/Missing/cabal.out

@@ -1,4 +1,4 @@
 # cabal check
 Warning: Unrecognised ignore "foo"
 These warnings will likely cause trouble when distributing the package:
-Warning: [short-description] The 'description' field should be longer than the 'synopsis' field. It's useful to provide an informative 'description' to allow Haskell programmers who have never heard about your package to understand the purpose of your package. The 'description' field content is typically shown by tooling (e.g. 'cabal info', Haddock, Hackage) below the 'synopsis' which serves as a headline. Please refer to <https://cabal.readthedocs.io/en/stable/cabal-package.html#package-properties> for more details.
+Warning: [short-description] The 'description' field should be longer than the 'synopsis' field. It's useful to provide an informative 'description' to allow Haskell programmers who have never heard about your package to understand the purpose of your package. The 'description' field content is typically shown by tooling (e.g. 'cabal info', Haddock, Hackage) below the 'synopsis' which serves as a headline. Please refer to <https://cabal.readthedocs.io/en/stable/cabal-package-description-file.html#package-properties> for more details.