Add Coddy to Learning Platforms

[ntnlbar]

Description

Adds Coddy to Learning Platforms. Coddy combines programming lessons with coding exercises that run in the browser and AI hints while practicing. It offers free learning content with optional premium features.

The combination of integrated exercises and AI hints is the reason for suggesting it alongside the existing learning platforms.

Disclosure: I’m Nethanel from Coddy.tech.

Type of change

• Add a new resource
• Update an existing resource
• Fix formatting/typos
• Improve categorization

Checklist

• I have read contributing.md.
• My change is specifically relevant to developer essentials.
• I used the format [Name](URL) - Description. for list entries.
• I checked for duplicate entries.
• Descriptions are concise, objective, and end with a period.
• I verified links are valid and not broken.
• I used canonical HTTPS URLs without shorteners or tracking parameters.
• I disclosed any affiliation with the added/updated resource.
• This pull request contains a single logical change.

Additional context

Add references or screenshots if they help review.

[CLAassistant]

All committers have signed the CLA.