Updated data structures in multiple files for better data handling. Also, switched license from GNU GPL v3 License to MIT License.

Under this commit, several changes have been made primarily in src/converter.rs, src/types.rs, config/settings/COPYRIGHT and various other files. The main action was the modification of various data structures as per requirements. Alongside this, the project license has been updated, switching from GNU GPL v3 License to MIT License across all the files.

[skip ci]

Signed-off-by: Lucas Greuloch (greluc) <lucas.greuloch@pm.me>