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* Some small developer QOL stuff.
* Better local development instructions in README.
* Remove docs from quality checks and ci.yml.
* Reasonable first pass at allowing for weak/strong admin editing ability depending on environment settings.
* Simple, first attempt at an idempotency key utility methods for ledgers and transactions that optionally take a subsidy and initial deposit, resp.
* Allow blank idp keys on the Ledger model, and set to a sane default if not provided on save().
* Remove JPY as an allowed unit.
* ``api.create_ledger()`` now seeds the ledger with an optional initial deposit.
* Check if we're already inside a transaction when setting ``durable=True`` in ``create_transaction()``.