Update README with compilation instructions

Added compilation instructions for SemiEuler using CMake and g++ on Windows.

Author: TimGoTheCreator

README.md

@@ -1,2 +1,16 @@
 # SemiEuler
 Semi implicit Euler implementation in C++ to simulate interaction of N-Body objects
+
+How to compile SemiEuler (CMake Windows)
+
+```bash
+mkdir build
+cd build
+cmake ..
+cmake --build .
+```
+How to compile SemiEuler G++ (Windows)
+
+```bash
+g++ -std=c++11 -O2 -Iinclude src/main.cpp -Llib -lraylib -lopengl32 -lgdi32 -lwinmm -lws2_32 -o SemiEuler.exe
+```