Improve the project's README

ReadMe.md

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+# About
+A recreation of the classic [Doom2D](https://doomwiki.org/wiki/Doom_2D) game from the late DOS era, a simulacrum of a parody - just as it should be.
+
+This open-source, multiplatform project has been developed from the ground up to recreate the original game while significantly enhancing gameplay, graphics, and introducing several new gamemodes. It features support for high-resolution graphics, improved AI, numerous fixes, and most importantly **online multiplayer**, revitalizing one of the biggest cult classics of ex-USSR.
+<p align="center">
+    <img src="https://doom2d.org/doom2d_forever/about/DFsml.jpg" alt="Doom2D Forever, SuperDM, 640x480.">
+</p>
+
+# Download and install
+Pre-built binaries of the latest commit (snapshot) are currently available for the following operating systems:
+- **Windows**: Download a ZIP-archive, either [Windows x64 (64-bit)](https://github.com/Doom2D/nixandroid/releases/latest/download/doom2df-mingw64.zip) or [**Windows x86 (32-bit)**](https://github.com/Doom2D/nixandroid/releases/latest/download/doom2df-mingw32.zip). Windows XP and newer is supported.
+- **Android**: Download the [**Android APK**](https://github.com/Doom2D/nixandroid/releases/latest/download/doom2df-android.apk). Android 4.0 and higher is supported.
+- **macOS**: Download the [**macOS ZIP archive**](https://github.com/Doom2D/nixandroid/releases/latest/download/doom2df-x86_64-apple-darwin.zip). Currently only x86-64 (Intel) binaries are provided. MacOS >= 11.0 is supported.
+
+# Disclaimer
+This game is a fair-use parody, licensed _strictly_ under terms of the [**GNU General Public License v3.0**](https://github.com/Doom2D/Doom2D-Forever/blob/master/COPYING).
+
+<a name="contacts"></a>
+# Contacts
+Join our [**Telegram**](https://t.me/doom2d) and [**Discord**](https://discord.gg/sGpJwMy) servers to discuss the development of the project.
+
+[![VK](https://img.shields.io/badge/Telegram-2CA5E0?style=flat-squeare&logo=telegram&logoColor=white)](https://t.me/doom2d)
+[![Discord](https://img.shields.io/badge/chat-Discord-8c9eff?logo=discord&logoColor=ffffff)](https://discord.gg/sGpJwMy)
+
+# Contribution and Development
+This repository is a place for everyone. If you want to contribute or need help, please join our [Telegram and Discord servers](#contacts).
+
+## Requirements
+For any possible build of Doom2D Forever you will need:
+
+- FPC >= 3.1.1
+- libenet >= 1.3.13
+
+## Build
+
+Please follow the instructions below to be able to build the project from source:
+
+Clone the project, and change your current working directory to project root.
+
+Create the `tmp` and `bin` directories and then run:
+
+```shell
+  cd src/game
+  fpc -O1 -g -gl -dDISABLE_SOUND -dUSE_SYSTUB -dUSE_GLSTUB -FE../../bin -FU../../tmp Doom2DF.lpr
+```
+
+If that command succeeds, you have a working FPC and libenet installation.
+## Compile-time switches
+### System driver
+|Switch          |What it does          |
+|----------------|----------------------|
+|`-dUSE_SDL2`    |Build with SDL 2.0.x  |
+|`-dUSE_SDL`     |Build with SDL 1.2.x  |
+|`-dUSE_SYSSTUB` |Disable I/O management|
+### Render driver
+|Switch         |What it does                  |
+|---------------|------------------------------|
+|`-dUSE_OPENGL` |Build with desktop OpenGL 2.x |
+|`-dUSE_GLES1`  |Build with mobile OpenGLES 1.1|
+|`-dUSE_GLSTUB` |Disable rendering             |
+### Sound driver:
+|Switch            |What it does                                         |
+|------------------|-----------------------------------------------------|
+|`-dUSE_FMOD`      |Build with FMOD Ex (4.30.22, other versions may fail)|
+|`-dUSE_SDLMIXER`  |Build with SDL_mixer                                 |
+|`-dUSE_OPENAL`    |Build with OpenAL 1.1                                |
+|`-dUSE_SOUNDSTUB` |Build with sound stub                                |
+|`-dDISABLE_SOUND` |Disable sound management                             |
+### OpenAL only
+|Switch                      |What it does                        |
+|----------------------------|------------------------------------|
+|`-dUSE_SDL2`                |Build with SDL 2.0.x for WAV support|
+|`-dUSE_SDL`                 |Build with SDL 1.2.x for WAV support|
+|`-dUSE_VORBIS`              |Build with libvorbis                |
+|`-dUSE_FLUIDSYNTH`          |Build with libfluidsynth            |
+|`-dUSE_MODPLUG`             |Build with libmodplug               |
+|`-dUSE_XMP`                 |Build with linxmp                   |
+|`-dUSE_MPG123`              |Build with libmpg123                |
+|`-dUSE_OPUS`                |Build with libopus                  |
+|`-dUSE_GME`                 |Build with libgme                   |
+|`-dOPENAL_SINGLETHREADED`   |Don't use threads for OpenAL        |
+### Other
+|Switch            |What it does                                                         |
+|------------------|---------------------------------------------------------------------|
+|`-dSDL2_NODPI`    |Build for old libSDL2                                                |
+|`-dUSE_MINIUPNPC` |Build with libminiupnpc for automatic server port forwarding via UPnP|
+|`-dENABLE_HOLMES` |Build with in-game map debugger                                      |
+|`-dHEADLESS`      |Build as headless executable for dedicated servers                    |
+
+## Runtime development flags
+- `--gdb`: prevents the game from handling exceptions.
+
+## Platform specific
+### OpenGLES
+Currently, OpenGLES depends uncoditionally on SDL2.
+### Android
+Currently, Android support depends unconditionally on SDL2.
+### Windows
+Windows binaries will require the appropriate DLLs (SDL2.dll, SDL2_mixer.dll or
+FMODex.dll, ENet.dll, miniupnpc.dll) unless you choose to link them statically.
+
+#### Static Linking
+It's now possible to link Windows' LibJIT and ENet as static libs.
+
+|Switch                        |What it does                               |
+|------------------------------|-------------------------------------------|
+|`-dLIBJIT_WINDOZE_STATIC`       |Static LibJIT                              |
+|`-dLIBENET_WINDOZE_STATIC`      |Static ENet                                |
+|`-dLIBMINIUPNPC_WINDOZE_STATIC` |Static MiniUPnPC                           |
+|`-dVORBIS_WINDOZE_STATIC`       |Static libogg/libvorbis (only in AL builds)|
+|`-dOPUS_WINDOZE_STATIC`         |Static libogg/libopus (only in AL builds)  |
+