Adapt README regarding CMake minimum version

* CMake minimum version has been decreased.

README.md

@@ -12,7 +12,7 @@ This project serves as a getting started demo for GitLab CI.
 
 ### Requirements
 
-* CMake >= 3.26.0
+* CMake >= 3.14.0
 * C++ Compiler >= C++14
 
 ### Install Dependencies