Allow the Contribution Tool URL to be configurable

[alessandrozago]

The URL for the contribution tool in the reporter module is written directly in the code. It would be nice to have it configurable in case a custom contribution tool is installed.
This is from src/reporter/index.js:8
const CONTRIBUTION_TOOL_URL = 'https://contribute.opentermsarchive.org/en/service';

This URL is used to create the link for "Edit the declaration" when opening an issue on the declarations repository.

Available for clarifications.

[Ndpnt]

Great suggestion! Making this configurable would indeed be a nice improvement. We could add a configuration option under the key @opentermsarchive/engine.reporter.contributionToolURL. Could you provide a pull request for this?