use EEX language configuration for LiveView templates

[oskarkook]

No description provided.

[axelson]

Thanks! They are very similar so I think this approach should work well. ❤️

[minhajuddin]

If anybody runs into this before a new version with this fix is included, add the following to your settings.json to get it working in the interim:

    "files.associations": {
        "*.leex": "HTML (EEx)"
    }