add a section about general code information

docs/dev/styleref.md

@@ -10,6 +10,18 @@
 - clang-tidy
 - linux / unix-like machine
 
+### code information
+The project is written in the [GNU dialect](https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html) of [C99](https://www.en.cppreference.com/w/c/99.html).
+Where we have dependencies on:
+| library                           | summary                                                 |
+|:----------------------------------|:--------------------------------------------------------|
+| [libarchive](libarchive.org)      | compression / decompression of various formats.         |
+| [glfw](https://www.glfw.org/)     | window creation / input handling.                       |
+| [openGL](https://www.opengl.org/) | hardware accelleration, for handling graphics.          |
+
+It is intended to be platform-agnostic, within reason. But the main focus is for [UNIX](https://unix.org/)-based systems with [x86_64](https://en.wikipedia.org/wiki/X86-64) architecture.
+Within [intdef.h](/src/util/intdef.h) there live definitions for static-width integer types.
+
 ### style guide
 - Code must be written correctly, read [Correct C](./correct-c.md) if more information is required.
 - K&R style braces/[indentation](https://en.wikipedia.org/wiki/Indentation_style)