Added blog smart contract

[AnmolSirola]

Description

A blogging smart contract which allows users to create a blog and post that blog . We can also create new blogs or update previous blogs we can also transfer the ownership of that blog to another person.

Fixes #133

Screenshots of relevant screens

Developer's checklist

• [x] My PR follows the style guidelines of this project
• [x] I have performed a self-check on my work

If changes are made in the code:

• [x] I have followed the coding guidelines
• [x] My changes in code generate no new warnings
• [x] I have added relevant screenshots in my PR