Most CMake files missed when categorizing by extension

[markdewing]

The cmake subdirectory contains files with the .cmake extension.
Most of the CMake logic to build projects is contained in files named CMakeLists.txt, which get placed in the text directory in this dataset.

In the dedup dataset, there are 186,517 files in cmake, while there are 469,291 files named CMakeLists.txt in the text directory.