Add support of initializing the extension on a Blueprint

[AlexJMohr]

Closes #24

Adds support for initializing the extension on a Blueprint.

Work in progress, wanted to get your input on a few things.

[CoultonF]

I tested out this change on a blueprint, and one thing to consider is that the template folder of a blueprint may not be tied to the current app template folder. In version.py this code should be changed to accommodate the blueprint as well.

def get_asset_version() -> str:
    """Calculate asset version to allow Inertia to automatically make a full page visit in case of changes."""
    template_path = os.path.join(
        current_app.root_path,
        current_app.template_folder,
        current_app.config["INERTIA_TEMPLATE"],
    )

return hashlib.sha256(bytes_content).hexdigest()

[AlexJMohr]

I tested out this change on a blueprint, and one thing to consider is that the template folder of a blueprint may not be tied to the current app template folder. In version.py this code should be changed to accommodate the blueprint as well.

def get_asset_version() -> str:
    """Calculate asset version to allow Inertia to automatically make a full page visit in case of changes."""
    template_path = os.path.join(
        current_app.root_path,
        current_app.template_folder,
        current_app.config["INERTIA_TEMPLATE"],
    )

return hashlib.sha256(bytes_content).hexdigest()

Addressed in 85c6165 but it's untested (blocked by #26)

[j0ack]

The changes seems good to me.

Could you also add a dedicated paragraph in the documentation adding the new feature (index.rst -> Configuration) and in the README ?