adds `eagr/sol-repl`

[eagr]

The repl currently listed is sadly unmaintained. Have created a new one that actually works, with a cleaner code base, less buggy, and more features.

Checklist

• [x] The URL is not already present in the list (check with CTRL/CMD+F in the raw markdown file).
• [x] Each description starts with an uppercase character and ends with a period.
  Example: solc-js - JavaScript bindings for the compiler.
• [x] Drop all A / An prefixes at the start of the description.
• [x] Avoid using the word Solidity in the description.

[bkrem]

Great stuff, thanks for providing an alternative REPL implementation for people 💪