Add Brandy to Design system tools

[adamhayek1]

Brandy is a new tool for designers to create brand guidelines and asset libraries to share with your team

Checklist

• [x] I made something good today 💐.
• [x] I put links in the correct format: [Tool](link) — description.
• [x] My description starts with the lower-case letter and ends with the full stop.
• [x] I put the tool in the alphabetical order.

Optional

• [x] I added the appropriate labels: free, open-source or mac.
• [x] I put the tool only to one category.
• [x] I followed Contribution Guidelines.