Adding new Include files
It is difficult to determine right or wrong as your description of what you have done lacks sufficient detail. However, file paths for inlcude files is added by right clicking the project name in the Project explorer tree and selecting Properties at the bottom of the menu or by left clicking on the project name in the Project explorer tree and pressing Alt+Enter. In the Properties dialog window left side, expand the > C/C++ Build catagory by clicking on the right arrow and select Settings in the indented list. To the right should appear some tabs under the Configuration: list box. Select the Tool Settings tab. Under the > MCU GCC Compiler heading select the Includes heading. To the right will appear the include file paths. A path can be editted by simply double clicking the path. A new path is added by using the add icon (depicting a document page with a green plus symbol) located to the right just below the scroll window containing the paths. A dialog window will appear that allows navigation within the file system or the workspace ( I prefer the later).