Improve the Qt for Android documentation

1) Qt 5.15 Qt for Android documentation contains some topics that have been documented also in Qt Creator side:--

• Setting up the environment:
  • Qt for Android: -[-https://doc-snapshots.qt.io/qt5-5.15/android-getting-started.html-] (Qt5.15 is not yet released so this link goes to the documentation snapshot area)-
  • Qt Creator: [-https://doc.qt.io/qtcreator/creator-developing-android.html-]
• Deployment
  • Qt for Android: -[-https://doc-snapshots.qt.io/qt5-5.15/deployment-android.html-]-
  • Qt Creator: -[-https://doc.qt.io/qtcreator/creator-deploying-android.html-]-
  • Both of the above mentioned topics are listed on page -[-https://doc-snapshots.qt.io/qt5-5.15/android.html-] (see "The following topics provide more details about how to use Qt for Android:") which might be confusign for the end user-
• --> it would be better to document Qt Creator related functionality in Qt Creator documentation and the Qt for Android related issues in the Android specific pages

2) Wiki lists some Qt for Android known issues (https://wiki.qt.io/Qt_for_Android_known_issues)

--> these could be added to the Qt for Android documentation, either by linking or by a listing them on https://doc-snapshots.qt.io/qt5-5.15/android-platform-notes.html#known-issues

3) Qt for Android related blog posts have useful information that could added to the documentation. For example,

• https://www.qt.io/blog/2019/06/28/comply-upcoming-requirements-google-play
• https://www.qt.io/blog/2017/12/01/sharing-files-android-ios-qt-app
  • see suggestion: https://bugreports.qt.io/browse/QTBUG-40537 - perhaps a new login example might be usefull too & the blog post content could be added to its documentation? Or then the blog post content could be a new topic in the Qt for Android documentation.