Update readme (#91)

Remove mentions of SDL2. Removed old MSVC and LINUX compile
instructions. All the dependencies are contained within the repo now so
the compilation instructions are a lot more simple.

Author: LiquidityC

LINUX_BUILD_INSTRUCTIONS.md

@@ -1,13 +1,14 @@
 [![maintenance](https://img.shields.io/badge/maintenance-passively--maintained-orange)](https://img.shields.io/badge/maintenance-passively--maintained-orange)
 [![CMake on multiple platforms](https://github.com/Oliveshark/breakhack/actions/workflows/cmake-multi-platform.yml/badge.svg)](https://github.com/Oliveshark/breakhack/actions/workflows/cmake-multi-platform.yml)
 
-Something in the ways of a roguelike
-================================
+![](header.jpg)
 
-A simple roguelike written in C using SDL2.
+---
+
+A simple roguelike written in C using SDL
+
+## Idea
 
-Idea
-----
 Randomly generated maps/rooms. Leveling system, permadeath,
 multiple classes. Casual and fun for 10-20 minutes during a break
 from regular work/play.
@@ -16,35 +17,41 @@ I wanted to practice C and I'm comfortable using SDL2. The assets
 are graciously taken from the web. More info in the README in the
 assets folder.
 
-Download
---------
+## Download
+
 This game is available in the [steam store](https://store.steampowered.com/app/931040/BreakHack/) (release Okt 2018).
 If you enjoy the game and want a properly installed, signed copy of the game with achievements and
 global highscores you are most welcome to purchase it there.
 If you feel like getting a free copy you can download and compile from here.
 
-Issues
-------
+## Issues
+
 I'd prefer if issues could be handled here on github. Either check the list if your particular problem is reported
 otherwise create a new issue. Support questions can be submitted as issues as well, I haven't figured out how I want to
 work with support yet since I haven't received any questions.
 
-License
--------
+## License
+
 BreakHack is released under two different licenses.
 
 - The source code is released under [GPLv3](https://github.com/oliveshark/breakhack/blob/master/LICENSE.txt)
 - The Steam release is released under the [Steam subscriber agreement](https://store.steampowered.com/subscriber_agreement/)
 
-Compile
--------
-* [Linux](LINUX_BUILD_INSTRUCTIONS.md)
-* [Windows (Visual Studio)](MSVC_BUILD_INSTRUCTIONS.md)
+## Compiling
+
+1. Ensure you have build tools installed. Git, gcc/clang, make/ninja, cmake.
+2. Checkout the repository (recursive): `git clone --recursive https://github.com/oliveshark/breakhack`
+3. Prepare build dir with cmake: `cmake -B build .`
+4. Build the project: `cmake --build build`
+
+Naturally if you have some experience with cmake you can configure and setup
+the build as you like. The above should be enough for anyone to copy/paste and
+get things running.
+
+## Contribute
 
-Contribute
-----------
 Have an idea and able to implement it? Fork and send me a pull request and
-I'll check it out. If I like it I will add it. If it's a big thing I'll add 
+I'll check it out. If I like it I will add it. If it's a big thing I'll add
 your name to the credits list (once I add it in game).
 
 If you do contribute something you should be aware that if your PR is merged
@@ -53,8 +60,7 @@ of the game. I don't make any revenue from those sales so don't expect any other
 than a "I have code on Steam" feeling. Which is quite nice and also why I decided to release
 on Steam.
 
-Links
------
+## Links
 
 - [Steam](https://store.steampowered.com/app/931040/BreakHack/)
 - [Itch.io](https://liquidityc.itch.io/breakhack)