x11 window and opengl initialization and drawing of basic quad

shader.h

@@ -0,0 +1,9 @@
+#pragma once
+
+typedef struct Shader {
+  int program;
+} Shader;
+
+void read_shader_file(const char *path, char **buf);
+Shader create_shader(const char *vertex_path, const char *fragment_path);
+void use_shader(Shader shader);