Use TOML configuration

slackbuilder.cabal

@@ -1,13 +1,11 @@
-cabal-version:      2.4
-name:               slackbuilder
-version:            0.1.0.0
-
--- A short (one-line) description of the package.
--- synopsis:
+cabal-version: 2.4
+name: slackbuilder
+version: 0.1.0.0
 
 -- A longer description of the package.
 -- description:
 
+synopsis: Slackware build scripts and configuration files.
 bug-reports: https://git.caraus.tech/OSS/slackbuilder/issues
 
 license: MPL-2.0
@@ -21,15 +19,19 @@ category: Build
 extra-source-files: CHANGELOG.md
 
 executable slackbuilder
-    main-is:          Main.hs
+    main-is: Main.hs
 
     other-modules:
         SlackBuilder.CommandLine
+        SlackBuilder.Config
         SlackBuilder.Updater
     default-extensions:
+        DataKinds
+        DuplicateRecordFields
         OverloadedStrings
         RecordWildCards
         TemplateHaskell
+        TypeApplications
     build-depends:
         aeson ^>= 2.2.0,
         base ^>= 4.16.4.0,
@@ -38,7 +40,8 @@ executable slackbuilder
         optparse-applicative ^>= 0.18.1,
         req ^>=3.13,
         text ^>= 2.0,
+        tomland ^>= 1.3.3,
         unordered-containers ^>= 0.2.19,
         vector ^>= 0.13.0
-    hs-source-dirs:   app
+    hs-source-dirs: app
     default-language: Haskell2010