Update constants.ts: fixed 404 error for DAO link by inluding i18n en…

[wunluv]

… path in link

On this screen: https://soliditylang.org/use-cases/ the "Learn more" link under Decentralised Autonomous Orgs points to:

• https://ethereum.org/dao/
• instead it should point to https://ethereum.org/en/dao/

This PR fixes this.

[r0qs]

… path in link

On this screen: https://soliditylang.org/use-cases/ the "Learn more" link under Decentralised Autonomous Orgs points to:

* https://ethereum.org/dao/

* instead it should point to https://ethereum.org/en/dao/

This PR fixes this.

Hi @wunluv why the link should be changed? The original works. Feel free to reopen this PR if there is a good reason to change the url.