[DOC] Write developer documentation for type hints including soft dependencies.

[MatthewMiddlehurst]

Describe the issue linked to the documentation

Developer documentation does not sufficiently include guidance for adding type hints, espceically in situations where soft dependencies are required.

Suggest a potential alternative/fix

Add a new page in docs/developer_guide/ on adding type hints. PyODAdapter is a good example of type hints with soft dependencies, following PEP 563.

[vedpawar2254]

@aeon-actions-bot assign @vedpawar2254

[SebastianSchmidl]

PR #2424 does not describe handling of soft-dependencies sufficiently.

typing.TYPE_CHECKING can be used to conditionally import soft-dependency types. However, to use those types, one must also always import from __future__ import annotations at the top of the file.

The example in the current documentation page does not include the usage of any conditionally-imported types. The displayed function is a input validation function and not related to the type-checking.

[vedpawar2254]

ok @SebastianSchmidl ill fix it

[MatthewMiddlehurst]

Ah yep, did not mean to close this, sorry.