Update README.md

[afmcdnl]

Added the MicroCode line in the visual languages.

Thanks!

Resource description

This is a new programming language development from the Microsoft team to encourage young people to code with the micro:bit.

By submitting this pull request I confirm I've read and complied with the below requirements 🖖

• [ X] I have read and understood the Contribution Guidelines
• [X ] I am making an individual pull request for each suggestion
• [ X] I have used the correct spelling and capitalisation for BBC micro:bit, micro:bit, and Micro:bit Educational Foundation (resource title could be excluded if there is a good reason)
• [ X] The content linked is in English, or it contains an English translation
• [ X] I have added the new entry to the bottom of its the category
• [ X] I have used the following format:

• Resource Title - Resource short Description (2 lines or less in total)

[afmcdnl]

Many thanks!

[afmcdnl]

Hope this works for Hacktoberfest 2022 - sorry for the multiple comments