Add new images to README.md file

[racbc]

Motivation

Wanted to fix the metdata typo from the PR opened in Aug 2021 (#78). Added images that are now in rosetta-api.org for Flow of Operations.

Solution

• Added new images to README.md file for Flow of Operations
• Stored new images in the /images folder
• Fixed metdata typo

[racbc]

Closing this pull request since #92 removes a lot of the information that this PR updates.