Write README

README

@@ -0,0 +1,25 @@
+                              ASTEROIDS
+
+This is a clone (ish) of the classic game Asteroids, written in C23
+for Linux.  To build the program, you'll need the Linux headers, a
+C23-compatible compiler and libdrm, along with its headers.  There is
+a build script that uses GCC; simply running this (`./build.sh`) is
+likely to work on many systems.
+
+The game directly uses Linux DRM, so it doesn't play nice with X,
+display managers etc.  You'll likely want to change to a virtual TTY
+and run the game from there rather than from inside a graphical
+session.  You may also need to add your user to the "input" group.
+
+
+                               CONTROLS
+                     +--------------------------+
+                     | forward           up     |
+                     | anti-clockwise    left   |
+                     | clockwise         right  |
+                     | fire              space  |
+                     |                          |
+                     | pause             p      |
+                     | quit              q      |
+                     | restart           r      |
+                     +--------------------------+