docs: Add build instructions

README.md

@@ -47,6 +47,8 @@ The user-facing API (functions defined in `minitar.h` and documented in this REA
 
 ## Documentation
 
+See the [build instructions](docs/Build.md) to start using minitar.
+
 See the [API documentation](docs/API.md) for a full description of all functions and types.
 
 ## Error handling

docs/Build.md

@@ -0,0 +1,42 @@
+# minitar build instructions
+
+minitar uses the cross-platform [CMake](https://cmake.org/) build generator.
+
+## Configuring
+
+Standard CMake out-of-source build:
+
+```sh
+$ mkdir -p build
+$ cmake -S . -B build
+```
+
+## Building
+
+Simply run `$ cmake --build build`.
+
+## Installing
+
+`# cmake --install build`
+
+This will (on UNIX-like platforms) install `minitar.h` to /usr/local/include, and `libmtar.a` to /usr/local/lib.
+
+## Using
+
+After installation, you can compile regular programs that include `minitar.h` and use the minitar API by adding the `-lmtar` flag to your compiler.
+
+Example:
+
+`cc -o my-own-tar my-own-tar.c -O2 -Wall -lmtar`
+
+## Using (with CMake)
+
+Add the `minitar` directory as a subdirectory of your project (perhaps using git submodules?) and add the following lines to your `CMakeLists.txt`:
+
+```
+add_subdirectory(minitar)
+
+target_link_libraries(<YOUR_PROJECT_NAME> PRIVATE minitar)
+```
+
+If you're using this method, this is the only step necessary, since minitar will be built and linked along with the rest of your project when you invoke your own build system.