removed nonfunctioning on-page nav

Author: tfosmark

docs/debugger/crt-debug-heap-details.md

@@ -135,8 +135,6 @@ The freed blocks kept unused in the debug heap's linked list when the `_CRTDBG_D
 New objects (0xCD)
 New objects are filled with 0xCD when they are allocated.
 
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 ![Back to top](../debugger/media/pcs_backtotop.png "PCS_BackToTop") [Contents](#BKMK_Contents)
 
 ## <a name="BKMK_Types_of_blocks_on_the_debug_heap"></a> Types of blocks on the debug heap