Add yaml and template based metadata creation

[jh-RLI]

Summary of the discussion

Introduce the create and creation modules to:

Step 1

• Get started with oemetadata when you only have your data resources as CSV files inside a directory or zipped directory, with or without nested directories -> Generate a YAML representation of the oemetadata which already describes your data .... but needs more details.
• Mainly describe data structure like: Column name, Column data type
• Ignore out certain files

Step 2

• Enhance your metadata by using the template section in the YAML file to apply metadata elements to all resources available in your data

Step 3

• Create oemetadarta v2 compliant JSON metadata

Type of change (CHANGELOG.md)

Added

• Add the creation module and create entry: They implement yaml based metadata creation, provide template feature to keep metadata creation DRY, provide functionality to setup the metadata structure & generate metadata from existingsources like datapackages and csv files, provide functionality to create the full datapackage.json and save it to file (#127)

Workflow checklist

Automation

Part of #126

PR-Assignee

• 🐙 Follow the workflow in CONTRIBUTING.md
• 📝 Update the CHANGELOG.md
• 📙 Update the documentation

Reviewer

• 🐙 Follow the Reviewer Guidelines
• 🐙 Provided feedback and show sufficient appreciation for the work done