Add references to the BG to OBJ section

Add references in the LCD Control section and the OAM section

Author: alloncm

src/LCDC.md

@@ -110,6 +110,8 @@ When Bit 0 is cleared, the background and window lose their priority -
 the sprites will be always displayed on top of background and window,
 independently of the priority flags in OAM and BG Map attributes.
 
+When Bit 0 is set [see background and window to obj priority](Tile_Maps.md#bg-to-obj-priority-in-cgb-mode).
+
 ## Using LCDC
 
 LCDC is a powerful tool: each bit controls a lot of behavior, and can be

src/OAM.md

@@ -122,4 +122,6 @@ This can be exploited to only hide parts of an object behind the background
 ([video demonstration](https://youtu.be/B8sJGgCVvnk)).
 A similar behaviour [can be seen on the NES](https://forums.nesdev.org/viewtopic.php?f=10&t=16861).
 
+**In CGB Mode**, BG vs. OBJ priority is declared in more than one register, [please see this page](Tile_Maps.md#bg-to-obj-priority-in-cgb-mode) for more details.
+
 :::