chore: Cleanup package and make it a native ESM package

* Drop unneeded .npmignore (`files` section of package.json overrides it anyways)
* Make package an ESM one (migrate config files to modules)
  * ESLint currently does not support an esm config, so use the json config instead
* Use `bundler` as Typescript resolution as we use rollup anyways

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

.eslintrc.json

@@ -0,0 +1,12 @@
+{
+	"extends": [
+		"@nextcloud/eslint-config/typescript"
+	],
+	"parserOptions": {
+		"babelOptions": {
+			"plugins": [
+				"@babel/plugin-syntax-import-assertions"
+			]
+		}
+	}
+}

.github/dependabot.yml

@@ -8,3 +8,4 @@ updates:
     time: "03:00"
     timezone: Europe/Paris
   open-pull-requests-limit: 10
+  versioning-strategy: increase

jest.config.js

@@ -1,4 +1,4 @@
-module.exports = {
+export default {
 	clearMocks: true,
 	collectCoverageFrom: ['lib/**/*.ts'],
 	coveragePathIgnorePatterns: ['lib/utils/logger.ts'],