fix: fix default export for ESM

[dword-design]

When i run

import endent from 'endent';

console.log(endent);

It will output { default: [Function: endent] { pretty: [Function (anonymous)] } } instead of just [Function: endent] { pretty: [Function (anonymous)].

It has to do with ESM-Commonjs interop. The project either needs to compile both (see dedent) or migrate to ESM. The PR migrates to ESM.