Feat/json produce support

[nanic]

Description

Support for produce with a json file is added, similar to csv we have to use --file in tandem with --file-type flag

Fixes #141 (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Documentation

• the change is mentioned in the ## [Unreleased] section of CHANGELOG.md
• the configuration yaml was changed and the example config in README.md was updated
• a usage example was added to README.md
• tests for the changes have been implemented (see: Testing your changes)

[d-rk]

⚠️ I rebased your branch

[d-rk]

@nanic thank you also for this PR. I just released a new version with your PRs included.