Add attachfocused patch.

This patch changes dwl to make new clients attach below the currently
focused one, like you can do on hyprland.

Finish readme

Add known issue to README

patches/attachfocused/attachfocused.patch

@@ -0,0 +1,29 @@
+From d03851c14073874f5b3d19a095e184dc24d219cd Mon Sep 17 00:00:00 2001
+From: MayOrMayNotBeACat <maybeacat804@gmail.com>
+Date: Sun, 11 May 2025 20:24:51 -0400
+Subject: [PATCH] Make new windows attach to active client
+
+---
+ dwl.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/dwl.c b/dwl.c
+index cf3ef70..1907c5f 100644
+--- a/dwl.c
++++ b/dwl.c
+@@ -1726,7 +1726,11 @@ mapnotify(struct wl_listener *listener, void *data)
+ 	c->geom.height += 2 * c->bw;
+ 
+ 	/* Insert this client into client lists. */
+-	wl_list_insert(&clients, &c->link);
++	Client* focused = focustop(selmon);
++	if (focused)
++		wl_list_insert(&focused->link, &c->link);
++	else
++		wl_list_insert(&clients, &c->link);
+ 	wl_list_insert(&fstack, &c->flink);
+ 
+ 	/* Set initial monitor, tags, floating status, and focus:
+-- 
+2.49.0
+