The new documentation style for publishing docs under qt.io
requires dedicated div classes for pages that use a three-
column layout.

The new divs enable the columns to stack and react to changes
in the window width.

Task-number: QTBUG-42086
Change-Id: Ic99a768e82e3eefaacff85458cb1cdf10b852318
Reviewed-by: Martin Smith <martin.smith@digia.com>

-lists examples that are specifically known to work on iOS
 (based from the list in qtbase/doc/global/manifest-meta.xml)
-focused on Qt Creator and Qt Quick examples.
-excluded Qt Widgets examples from the list
-added links to this new page.

Change-Id: I9d9d775dafd6c6573e2c45ea75756f189e4d07d4
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>

-more functional with regards to a developer progression.
-added link to "Creating a Mobile Application" page.

Change-Id: I8a1b5261df96459592ae253f6a19b57909c51173
Reviewed-by: Martin Smith <martin.smith@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

-list taken from manifestmeta.android.names variable from
 qtbase/doc/global
-doesn't include all of the examples tagged for Android; focus is on
 QML examples

Change-Id: I4f58af21840f7df903d16ca530f8fa7f4c7aaa37
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>