Add build instructions

Author: DolphinChips

BUILDING.md

@@ -0,0 +1,31 @@
+# Building
+
+## Windows
+
+Prerequsites:
+* Installation of Visual Studio Build Tools
+* CMake (available with VS Build Tools)
+* vcpkg (available with VS Build Tools)
+* `VCPKG_ROOT` environment variable pointing at vcpkg installation folder
+
+### With CMake CLI
+With Developer PowerShell open at root folder of this project run:
+```pwsh
+cmake -Bbuild -S. -DCMAKE_TOOLCHAIN_FILE="$env:VCPKG_ROOT\scripts\buildsystems\vcpkg.cmake" -DVCPKG_TARGET_TRIPLET=x64-windows-static-md
+cmake --build build
+```
+Resulting binary will be located at `build/src/System/Debug/ArrowVortex.exe`
+
+To install ArrowVortex to a folder run:
+```pwsh
+cmake --install build --prefix "<your_folder_here>"
+```
+
+### With Visual Studio
+1. Run `vcpkg integrate install` in Developer PowerShell. This will integrate vcpkg with your installation of Visual Studio and needs to be run once.
+2. Open root folder of this project in Visual Studio
+
+
+## Troubleshooting
+### CMake can't find freetype
+CMake failed to integrate with vcpkg. Remove your build directory (either `build/` or `out/`) and follow instructions for your system.