Correct markdown misinterpretation.

The term “#define”, when the line breaking happens to put at the
beginning of a line, confuses markdown. This change escapes the '#'.

Change-Id: I8300324f9e8c7561f32aba6fa29c0132a188a58b

INCORPORATING.md

diff --git a/INCORPORATING.md b/INCORPORATING.md
index ef36aa3..58f37db 100644
--- a/INCORPORATING.md
+++ b/INCORPORATING.md
@@ -50,7 +50,7 @@
 
 BoringSSL does not present a lot of configurability in order to reduce the
 number of configurations that need to be tested. But there are a couple of
-#defines that you may wish to set:
+\#defines that you may wish to set:
 
 `OPENSSL_NO_ASM` prevents the use of assembly code (although it's up to you to
 ensure that the build system doesn't link it in if you wish to reduce binary