docs: write stuff in the README.md

Author: RiscadoA

README.md

@@ -1 +1,25 @@
-# cubos-demo
+# Cubos Demo Repository
+
+This repository holds the games we built with **Cubos**, both internally, or while participating in external events or game jams.
+Most of these games can be played on the browsed or downloaded on our [itch.io](https://cubos-engine.itch.io/).
+
+Currently, this repo holds the following games:
+- **Scraps vs Zombies** - [Released](https://riscadoa.itch.io/scraps-vs-zombies).
+- **Ondisseia** - [Released](https://riscadoa.itch.io/ondisseia).
+- **Roll Racers** - [Released](https://riscadoa.itch.io/roll-racers).
+- **Airships** - unfinished, work in progress!
+- **Cars** - the first game we made with **Cubos**, a very basic racing game.
+
+## Building
+
+To build the demos you need to first separately install the **Cubos Engine** using *CMake*.
+Then, when building this repository, you might need to help *CMake* find the installation directory of **Cubos**.
+By default, all demos are compiled - you might disable any of them using their respective *CMake* option.
+
+We recommend building both the engine and the demos in Release - when developing, Release with Debug Information is usually enough to debug any errors that show up.
+
+## Distributing
+
+When compiling the game during development, paths to assets directories are hardcoded into the produced binaries.
+This means that the produced binaries are not portable and won't work on other machines.
+To create a portable installation of the game, enable the *CMake* option `DISTRIBUTE`, and then install the project through *CMake*.