Migrate Prettier config to .mjs

Author: hasparus

prettier.config.mjs

@@ -0,0 +1,7 @@
+import guildConfig from '@theguild/prettier-config';
+
+export default {
+  ...guildConfig,
+  overrides: [{ files: '*.json', options: { trailingComma: 'none' } }, ...guildConfig.overrides],
+  importOrderParserPlugins: ['explicitResourceManagement', ...guildConfig.importOrderParserPlugins],
+};