Add build scripts for Windows

Specify command for building in Windows without depending on the IDE.

.gitignore

@@ -64,3 +64,4 @@ assets_wip/
 Backup_*.cdr
 .DS_Store
 *.sqlite
+build/

00-build-cache-debug-x64.bat

@@ -0,0 +1 @@
+cmake -DPROJECT_SOURCE_DIR=. -DCMAKE_SIZEOF_VOID_P=8 "-DCMAKE_MT=%CMAKE_MT%" -DCMAKE_BUILD_TYPE=Debug -DCMAKE_MAKE_PROGRAM=ninja -DCMAKE_C_COMPILER=clang-cl -DCMAKE_C_COMPILER_WORKS=1 -DCMAKE_C_FLAGS=-m64 -G Ninja -S . -B ./build/Debug

01-build-game.bat

@@ -0,0 +1 @@
+cmake --build build/Debug -t game

02-build-server.bat

@@ -0,0 +1 @@
+cmake --build build/Debug -t server

README.md

@@ -8,6 +8,16 @@ A run-and-gun shooter inspired by Metal Slug.
 
 ### Windows
 
+The following tools are required:
+
+* CMake
+* Ninja
+* Clang
+  > Set your `CC` environment variable to the full path of `clang-cl.exe`
+ 
+  > Set your `CMAKE_MT` environment variable to the full path of `mt.exe`, which can be found on your Windows SDK
+	> installation folder (usually `C:/Program Files (x86)/Windows Kits/10/bin/10.0.19041.0/x86/mt.exe`)
+
 1. Clone this repo.
 2. Clone the repositories under `dependencies.txt` except for SDL2.
 3. Unpack the **MSVC** archive under `dependencies` folder in this project's root. Rename the directory as `SDL2`.