Airdrop

[Griffsano]

Closes #104, #132

To-do list

• Change documentation in readme
• Read-in configuration files to define if airdrops are taxable
• Match airdrops to configurations from files
• Change default taxation of airdrops to taxable (if no entry is found in the configuration files)
• Implement taxation of taxable airdrops (both buy and sell behavior)

[provinzio]

Default value needs to be defined in init. If you define it here. It's a general class variable. Alle classes share this variable / or define it as taxable: bool = True without type annotation it's a class wide variable.

https://stackoverflow.com/questions/61937520/proper-way-to-create-class-variable-in-data-class