feat: add CMake

CMakeLists.txt

+cmake_minimum_required(VERSION 3.10)
+project(sibyl C)
+
+set(CMAKE_C_STANDARD 11)
+add_subdirectory(common)
+add_subdirectory(clients)
\ No newline at end of file

README.md

 # Embedded Linux Project (sibyl)
+
+## Building
+
+### Kernel Module
+```bash
+cd kernel
+make
+sudo make install
+```
+
+### Userspace
+```
+mkdir build && cd build
+cmake ..
+make
+```
+
+The binaries will be in:
+- `build/daemon/daemon`
+
+- `build/clients/*`

clients/CMakeLists.txt

+add_subdirectory(cpu_temp)
\ No newline at end of file

clients/cpu_temp/CMakeLists.txt

+add_executable(cpu_temp
+    src/cpu_temp.c
+)
+target_link_libraries(cpu_temp
+    PRIVATE common
+)
+target_include_directories(cpu_temp
+    PRIVATE include
+)
\ No newline at end of file

common/CMakeLists.txt

+add_library(common
+    src/protocol.c
+)
+target_include_directories(common
+    PUBLIC include
+)
\ No newline at end of file