Introducing an option for the user to decide on simplifying GADM shap…

…es (#1138)

* docs(contributor): contrib-readme-action has updated readme

* feature: Introducing configurable option to simplify GADM shapes

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* docs(contributor): contrib-readme-action has updated readme

* Adding 'simplify_gadm' description to configtables

* doc: Release note update

* docs(contributor): contrib-readme-action has updated readme

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Set simplify_gadm to true by default