Add directory name in index.js

[guest271314]

Kindly substitute

    const e = require(`${__dirname}/engines/${f}`);

or

    const e = require(`${path.join(__dirname, 'engines')}/${f}`);

for

esvu/src/index.js

Line 13 in 09a20f3

const e = require(`./engines/${f}`);

Bun's bun bundle and bun bundle --compile wind up throwing

Cannot find module "./engines/boa.js" from "/$bunfs/root/esvu"

when running the executable from --compile, and

Cannot find module "./engines/boa.js" from "/home/user/esvu_bundle.js"

when just running bun build to bundle, oven-sh/bun#13672.

(deno throws for the bundle command with 3: Module "file:///home/user/node_modules/esvu/dist/src/bin.js" was an unsupported module kind. though is about to compile successfully with deno compile npm:esvu).