fix: build the action with rollup

On v4, we used the default nodejs resolution logic to allow ES modules in dependencies.
This created a breaking change of forcing users of this action
to use the .cjs extension instead of .js in config files.

With this fix, we now bundle the action with rollup to allow ES modules
in dependencies, while keeping the support for .js config files.

With this change, the default config file was returned back to .js instead of
.cjs.

Fixes #194

action.yml

@@ -3,19 +3,20 @@ description: Lints Pull Request commit messages with commitlint
 author: Wagner Santos
 inputs:
   configFile:
-    description: Commitlint config file. If the file doesn't exist, config-conventional settings will be
+    description:
+      Commitlint config file. If the file doesn't exist, config-conventional settings will be
       loaded as a fallback.
-    default: ./commitlint.config.cjs
+    default: ./commitlint.config.js
     required: false
   firstParent:
     description: >
       When set to true, we follow only the first parent commit when seeing a merge commit. More info
       in git-log docs https://git-scm.com/docs/git-log#Documentation/git-log.txt---first-parent
-    default: "true"
+    default: 'true'
     required: false
   failOnWarnings:
     description: Whether you want to fail on warnings or not
-    default: "false"
+    default: 'false'
     required: false
   helpURL:
     description: Link to a page explaining your commit message convention