Fix page navigation links for Target Platforms
Fix page navigation links for Target Platforms

The user manual defines a strict navigation flow. The "Target Platforms"
document was added only recently, but it wasn't properly integrated.

Change-Id: I69edb60fddba0f012d25dce5a91ed746d54abe87
Reviewed-by: Leena Miettinen <885fda02d52616fec24ed5fed9b3f0568fce3ead@qt.io>

qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs