Update dependency management documentation in ONNX Runtime

Author: Changming Sun

docs/build/dependencies.md

@@ -1,6 +1,6 @@
 # Dependency Management in ONNX Runtime
 
-This document provides additional information to CMake’s [“Using Dependencies Guide”](https://cmake.org/cmake/help/latest/guide/using-dependencies/index.html)  with a focus on ONNX Runtime. There are three main ways to obtain C++ dependencies for an ONNX Runtime build:
+This document provides additional information to CMake’s [“Using Dependencies Guide”](https://cmake.org/cmake/help/latest/guide/using-dependencies/index.html)  with a focus on ONNX Runtime. ONNX Runtime uses a lot of open source C++ libraries. For example, abseil, protobuf, re2, onnx, etc. There are three main ways to obtain them for an ONNX Runtime build:
 
 1. [Use VCPKG](#vcpkg) (Recommended)
 2. [Build everything from source](#build-everything-from-source)