Add support for npm-groovy-lint (#4495)

* Add support for npm-groovy-lint

* Add doc and tests for npm-groovy-lint

* Use ale#util#FuzzyJSONDecode instead of json_decode

autoload/ale/fix/registry.vim

@@ -610,6 +610,11 @@ let s:default_registry = {
 \       'function': 'ale#fixers#rustywind#Fix',
 \       'suggested_filetypes': ['html'],
 \       'description': 'Sort Tailwind CSS classes',
+\   },
+\   'npm-groovy-lint': {
+\       'function': 'ale#fixers#npmgroovylint#Fix',
+\       'suggested_filetypes': ['groovy'],
+\       'description': 'Fix Groovy files with npm-groovy-fix.',
 \   }
 \}