Use deno_std path module?

Would you mind switch to use `deno_std`'s path module? API is compatible with Node.js, simply use `deno bundle` to output es module, make bundlers do tree shaking better

```ts
// mod.ts
import { win32, posix } from 'https://deno.land/std@0.163.0/path/mod.ts'

export { win32, posix }

export const {
basename,
delimiter,
dirname,
extname,
format,
fromFileUrl,
isAbsolute,
join,
normalize,
parse,
relative,
resolve,
sep,
toFileUrl,
toNamespacedPath
} = posix
```

```bash
deno bundle mod.ts index.js
```

```jsonc
// package.json
{
"module": "./index.js",
"main": "./index.js",
"type": "module"
}
```

Start by comparing the current module entry point with the proposed mod.ts exports, then review package.json and the deno bundle command. Confirm the deno_std path API works for the package's existing consumers and that the generated ES module and package metadata preserve the current interface.

索引モデルが issue の本文から書いたものです。