Add changelog for #4024 and update register_page docstrings

[AnnMarieW]

No code changes - just add changelog and updated docstring for PR #4024

Does this need to be updated too? https://github.com/plotly/dash/blob/dev/.ai/ARCHITECTURE.md#dash-constructor-parameters

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[T4rk1n]

No code changes - just add changelog and updated docstring for PR #4024

Does this need to be updated too? https://github.com/plotly/dash/blob/dev/.ai/ARCHITECTURE.md#dash-constructor-parameters

Yes, the AI documentation should follow, altho I am not sure of listing all the arguments like that is really useful and the document is getting too big. I'd vote to actually remove that section, AI can grep the constructor easily and it can drift.

Instead I'd improve this section: https://github.com/plotly/dash/blob/dev/.ai/ARCHITECTURE.md#meta-tag-sanitization with the details how it works.

[AnnMarieW]

Should we just leave the AI docs update for a different PR?

[T4rk1n]

Should we just leave the AI docs update for a different PR?

Yes, I created #4051 to track it.

[T4rk1n]

💃