Add Cabal, Cabal-syntax, cabal-install and cabal-install-solver to core libraries

As per https://groups.google.com/g/haskell-core-libraries/c/vqyNHUeNC2E/m/HRcL1-J9AQAJ

Author: Bodigrim

README.md

@@ -52,6 +52,10 @@ Current list of Core Libraries:
 * `array`,
 * `binary`,
 * `bytestring`,
+* `Cabal`,
+* `Cabal-syntax`,
+* `cabal-install`,
+* `cabal-install-solver`,
 * `deepseq`,
 * `directory`,
 * `entropy`,