Enrich the documentation with more educational content

The documentation should include detailed guides for different features on Qt for Android. This includes snippets for easy configuration. The documentation should state clearly what features are available and working on Android and what issues/bugs are known.

Below is a list of important parts to improve, but the list is open.

Android Services

• Qt Android services page is short and limited, we should provide enough code snippets for users to easily set the environment. Also, it's good practice to list known issues/bugs such as QTBUG-78009

Connecting Android Devices

• ./android tool is deprecated, instead, use sdkmanager and ndkmanager
• Update screenshots with newer versions of Qt
• On Linux: instruct to provide permissions to /dev/kvm to properly run the emulator

Also, the writing structure could be improved to avoid big chunks of text with bad formats that are hard to read.