It is possible to add a slider to you website by using the 'Bootstrap Slider' element, which can be found below 'Content elements' when creating a new element. (1.6.1)
In the 'General' tab you can see the content element type 'Bootstrap Slider' selected (1). (1.6.2)
The element has the name field (2) - but it is not visible in frontend. When you have several slides, in 'Additional settings' you can set the time interval (3) between showing slides and with the help of 'Quickselect' (4) checkbox you can make slides available by clicking points (like in image 1.6.3)
You can add a picture to the Slider when being on the 'Slides' tab and clicking on 'Add image'. There you can select one or multiple images from the file list. (1.6.4)
To add text content to your Slide (after selecting an image) onto the picture you will find the information below the picture. If you can't see it, click on the grey bar (1) to expand the information. On the right hand side of the grey bar, you can find icons to handle the image: like editing, hiding, deleting and moving the files (2). To add a header text, you write the header in the 'Title' field (3). If you wish to have sub header, use the 'Alternative text' field (4). A link can be placed in the link field (5) and the text can be written in the description field (6), which is a plain text field, and it is not possible to format this text with row breaks, linked text or any type of text transformation. All fields are optional.
It is also possible to crop the image (to select the ratio and the area you want) by selecting the "Open Editor" button (7) inside the image information. Beside that you can set the 'Size of images' (8): width and height (1.6.5)