add build instructions

BUILD_INSTRUCTIONS.md

@@ -0,0 +1,58 @@
+# Build Instructions 
+
+## * Requirements
+
+- [git](https://git-scm.com/)
+- [git-lfs](https://git-lfs.github.com/)
+- [cmake](https://cmake.org/) **>= 3.11**
+- [gcc](https://www.gnu.org/software/gcc/) **>= 4.9** or [clang](https://clang.llvm.org/) **>= 3.8** or [msvc](https://visualstudio.microsoft.com/) **>= 2015**
+
+## * Cloning
+
+```bash
+$ git clone --recursive git://github.com/enduro2d/enduro2d-bootstrap.git
+$ cd enduro2d-bootstrap
+```
+
+> or
+
+```bash
+$ git clone git://github.com/enduro2d/enduro2d-bootstrap.git
+$ cd enduro2d-bootstrap
+$ git submodule update --init --recursive
+```
+
+## * Building
+
+```bash
+$ cd your_bootstrap_repository_directory
+$ mkdir build && cd build
+$ cmake -DCMAKE_BUILD_TYPE=Release ..
+$ cmake --build . -- -j8
+
+# also you can generate Xcode project
+$ cd your_bootstrap_repository_directory
+$ mkdir xcode-build && cd xcode-build
+$ cmake -G Xcode ..
+$ open enduro2d-bootstrap.xcodeproj
+
+# or Visual Studio project
+$ cd your_bootstrap_repository_directory
+$ mkdir msvc-build && cd msvc-build
+$ cmake -G "Visual Studio 15 2017" ..
+$ start enduro2d-bootstrap.sln
+```
+
+## * Running
+
+```bash
+$ cd your_bootstrap_build_directory
+$ ./enduro2d-bootstrap
+```
+
+## * Links
+
+- CMake: https://cmake.org/
+- CMake documentation: https://cmake.org/documentation/
+- CMake FAQ: https://gitlab.kitware.com/cmake/community/wikis/FAQ
+