Add Solidity oracle project

[01231]

Description

The pr adds a new project for the solidity programming language.

Motivation and Context

Solidity is a widely used language for smart contract development and becomes more popular every day! It is therefore important to provide interesting project to the community.

How Has This Been Tested?

Types of changes

• [ ] Content Update (change which fixes an issue or updates an already existing submission)
• [x] New Article (change which adds functionality)
• [ ] Documentation change

Checklist:

• [x] My code follows the code style of this project.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have made checks to ensure URLs and other resources are valid