Image assets fail to load from CDN since they’re pointing to the old repo

Image assets within instruction pages are failing to load:

The issue is simply due to the `githubPath` specified in `package.json` still being: `"EagerIO/EmbedBox"`.

https://github.com/cloudflare/embed-box/blob/f669c7edc93934632852cc0675a269f2bce4639f/package.json#L21

This path is then used to construct the asset CDN URL:

https://github.com/cloudflare/embed-box/blob/f669c7edc93934632852cc0675a269f2bce4639f/webpack.config.base.js#L6
https://github.com/cloudflare/embed-box/blob/f669c7edc93934632852cc0675a269f2bce4639f/webpack.config.base.js#L17

This image fails to load:

```txt
https://cdn.rawgit.com/EagerIO/EmbedBox/v2.0.3/dist/assets/app/targets/shopify/shopify-latest/edit-template.png
```

(It redirects to `https://cdn.jsdelivr.net/gh/EagerIO/EmbedBox/...` which fails to load.)

However, with the correct repo path, it loads:

```
https://cdn.rawgit.com/cloudflare/embed-box/v2.0.3/dist/assets/app/targets/shopify/shopify-latest/edit-template.png
```