update TODO

TODO.md

@@ -3,3 +3,7 @@ Performance:
 * libuv allocates on every read, we should use a read buffer pool
 * update cells for drawing should just happen once per frame
 * update cells should only update the changed cells
+
+Correctness:
+
+* `exit` in the shell should close the window

src/Window.zig

@@ -129,7 +129,7 @@ pub fn create(alloc: Allocator, loop: libuv.Loop) !*Window {
         return error.CommandNotFound;
     defer alloc.free(path);
 
-    var env = std.BufMap.init(alloc);
+    var env = try std.process.getEnvMap(alloc);
     defer env.deinit();
     try env.put("TERM", "dumb");