convert more spoiler into deobfuscation

bugs.md

@@ -3508,8 +3508,8 @@ Also, it requires a space between identifiers.  In short, use `(S K)` instead of
 
 Huge memory may be required to compile the program (about 300 MB on my machine).
 
-In addition, there are some limitations (and workarounds) mentioned in [Spoiler
-section](2013/endoh1/index.html#spoiler).
+In addition, there are some limitations (and workarounds) mentioned in the
+[Deobfuscation section](2013/endoh1/index.html#deobfuscation).
 
 --