Remove/deprecate this package in favor of minimap-pigments

Hi,

Since `atom-color-highlight` is not available in the atom packages repo anymore, this package doesn't work. Please remove it and add deprecation notice to avoid confusion. Thanks

The issue is about deprecating the minimap-color-highlight package because its dependency atom-color-highlight is unavailable. First, examine the package.json to understand the current setup and dependencies. Then, look for where deprecation notices can be added, possibly in the README or package metadata. Finally, consider removing the package from the Atom packages repo, which may involve repository settings or publishing steps.

索引モデルが issue の本文から書いたものです。