Most CMake files missed when categorizing by extension

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.
