Implement fallback install and outputs (#2)

* Add better version support. Restructure code. Implement OS agnostic fallback

* Support latest for cabal and stack. Add enable-stack option.

* Add outputs

* Update documentation. Change default for GHC to latest.

.lintstagedrc.js

@@ -0,0 +1,6 @@
+module.exports = {
+  '!(*test).{js,ts}': 'eslint --cache --fix',
+  '!(*test).ts': () => ['ncc build', 'git add dist'],
+  'src/**/*.ts': () => 'tsc -p tsconfig.json',
+  '*.{js,ts,json,md}': 'prettier --write'
+};