ScanAndLoadShaderFiles: add a comment near the shader table initializ…

…ation explaining which behaviour is produced

src/engine/renderer/tr_shader.cpp

@@ -5551,6 +5551,7 @@ static void ScanAndLoadShaderFiles()
 			shaderTable_t *tb;
 			bool      alreadyCreated;
 
+			// zeroes all shaders, booleans can be assumed as false
 			Com_Memset( &table, 0, sizeof( table ) );
 
 			token = COM_ParseExt2( &p, true );