README: remove a dead URL (#85)

Closes #79.

README.md

@@ -155,13 +155,13 @@ $ ulimit -c unlimited
 ```
 
 ###### Windows:
+
 Merge `tools/win_enable_dumps.reg` into your registry. Note that this will disable the Windows Error Reporting dialog when a program crashes, so it's recommended that you do this in a VM if you want to keep that enabled.
 
 ## Current Status
 
-Porting the Challenge Binaries is a work in progress, and the current status of the porting effort is tracked in the following spreadsheet:
-
-https://docs.google.com/spreadsheets/d/1Z2pinCkOqe1exzpvFgwSG2wH3Z09LP9VJk0bm_5jPe4/edit?usp=sharing
+Porting the Challenge Binaries is a work in progress. Please help us out by
+reporting any build and/or behavior errors you discover!
 
 ## Notes