Improve README.md (emojis + quality section)

[ccamel]

Purpose

The README.md file could be enhanced in the following ways:

• Emojis are used for some section headers, but not all. It would be beneficial to add emojis to the remaining section titles for consistency.

• A section should be added to describe the quality assurance approach used in this project, which ensures that the Smart Contracts developed meet high-quality standards. The section should especially mention that this is achieved through:
  • The enforcement of stringent rules, monitored by a linter (Clippy) within the Github CI environment.
  • A high level of code coverage through systematic unit testing.
  • Future considerations for additional testing approaches, such as fuzzy testing or end-to-end testing, to further enhance quality.

[jeremylgn]

#384 ☑️