Update README.txt

Change description
Merge branch 'master' of https://github.com/yudjin87/carousel
Implementation of forgiven methods added.
CommandCatalog has been implemented, tests have been added.
Hide helping method.
Support for popup/context menu added.
Tests and implementation for the support for popup/context menu added.
Find command by name in the command catalog.
Disable copy for the command catalog.
Interactive component contract has been added.
Using reference instead of pointer.
IConfigurator interface has been added.
API documentation has been changed a little.
ConfiguratorBase class has been added.
Add empty methods, clarify API.
add() method returns QToolBar instead of action.
4 spaces in the API documentation have been replaced with 3 spaces for the correct doxygen markup.
Disable copying.
DockWidgetCatalog has been added, tests have been implemented for it.
Rename DockWindowCatalog to the DockWidgetCatalog