doc: add dependency for PDF in contributing guide
-rw-r--r-- 48 .gitattributes
-rw-r--r-- 356 .gitignore
-rw-r--r-- 291 GNUmakefile
-rw-r--r-- 37277 MAINTAINERS
-rw-r--r-- 136 Makefile
-rw-r--r-- 510 README
drwxr-xr-x - app
drwxr-xr-x - buildtools
drwxr-xr-x - config
drwxr-xr-x - devtools
drwxr-xr-x - doc
drwxr-xr-x - drivers
drwxr-xr-x - examples
drwxr-xr-x - kernel
drwxr-xr-x - lib
drwxr-xr-x - license
-rw-r--r-- 4058 meson.build
-rw-r--r-- 1912 meson_options.txt
drwxr-xr-x - mk
drwxr-xr-x - test
drwxr-xr-x - usertools