skeleton for reusable elements
we created a somehow nice button
This, doesn't work.  git add main.cpp qml/reusable_elements/main.qml The reusable elements need to have their name starting with an upper case.
NO: button.qml => Yes: Button.qml
this is better
with the right .pro file
changed look of the button
added a property to
  * change the color at the creation
  * change the text of the Text area (we don't have access to it in the parent)
using the buttons
Be careful git add qml/reusable_elements/Button.qml Properties given at the construction override the ones in the object.
Here, the anchors.left in the Button.qml won't change anything.
This can be very tricky sometimes
end on the reusable elements
skeleton for signal slots