introduce how to build with Vulkan on Raspbian OS

```
cmake -B build -DBUILD_SHARED_LIBS=OFF -DLLAMA_CURL=OFF -DGGML_VULKAN=1
```

```
-- The C compiler identification is GNU 12.2.0
-- The CXX compiler identification is GNU 12.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found Git: /usr/bin/git (found version "2.39.5")
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Warning: ccache not found - consider installing it for faster compilation or disable this warning with GGML_CCACHE=OFF
-- CMAKE_SYSTEM_PROCESSOR: armv7l
-- GGML_SYSTEM_ARCH: ARM
-- Including CPU backend
-- Found OpenMP_C: -fopenmp (found version "4.5")
-- Found OpenMP_CXX: -fopenmp (found version "4.5")
-- Found OpenMP: TRUE (found version "4.5")
-- ARM detected
-- Performing Test GGML_COMPILER_SUPPORTS_FP16_FORMAT_I3E
-- Performing Test GGML_COMPILER_SUPPORTS_FP16_FORMAT_I3E - Success
-- Performing Test GGML_MACHINE_SUPPORTS_dotprod
-- Performing Test GGML_MACHINE_SUPPORTS_dotprod - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_nodotprod
-- Performing Test GGML_MACHINE_SUPPORTS_nodotprod - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_i8mm
-- Performing Test GGML_MACHINE_SUPPORTS_i8mm - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_noi8mm
-- Performing Test GGML_MACHINE_SUPPORTS_noi8mm - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_sve
-- Performing Test GGML_MACHINE_SUPPORTS_sve - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_nosve
-- Performing Test GGML_MACHINE_SUPPORTS_nosve - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_sme
-- Performing Test GGML_MACHINE_SUPPORTS_sme - Failed
-- Performing Test GGML_MACHINE_SUPPORTS_nosme
-- Performing Test GGML_MACHINE_SUPPORTS_nosme - Failed
-- ARM feature FMA enabled
-- Adding CPU backend variant ggml-cpu: -mfp16-format=ieee;-mcpu=cortex-a7
-- Found Vulkan: /usr/lib/arm-linux-gnueabihf/libvulkan.so (found version "1.3.239") found components: glslc glslangValidator
-- Vulkan found
-- GL_KHR_cooperative_matrix not supported by glslc
-- GL_NV_cooperative_matrix2 not supported by glslc
-- GL_EXT_integer_dot_product not supported by glslc
-- GL_EXT_bfloat16 not supported by glslc
-- Including Vulkan backend
-- ggml version: 0.0.6123
-- ggml commit:  79c1160
-- Configuring done
-- Generating done
-- Build files have been written to: xxx/llama/llama.cpp/build
```

docs/build.md

@@ -395,6 +395,11 @@ First, follow the official LunarG instructions for the installation and setup of
 > [!IMPORTANT]
 > After completing the first step, ensure that you have used the `source` command on the `setup_env.sh` file inside of the Vulkan SDK in your current terminal session. Otherwise, the build won't work. Additionally, if you close out of your terminal, you must perform this step again if you intend to perform a build. However, there are ways to make this persistent. Refer to the Vulkan SDK guide linked in the first step for more information about any of this.
 
+If you want to build on the Raspbian OS, you can just run the following commands to install Vulkan SDK:
+```
+sudo apt install libvulkan-dev glslc glslang-tools
+```
+
 Second, after verifying that you have followed all of the SDK installation/setup steps, use this command to make sure before proceeding:
 ```bash
 vulkaninfo