Various documentation fixes.

Add some missing headers and ensure each header has a short description. doc.go
gets confused at declarations that break before the first (, so avoid doing
that. Also skip a/an/deprecated: in markupFirstWord and process pipe words in
the table of contents.

Change-Id: Ia08ec5ae8e496dd617e377e154eeea74f4abf435
Reviewed-on: https://boringssl-review.googlesource.com/2839
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/bytestring.h b/include/openssl/bytestring.h
index d5e6cf9..2bff3f5 100644
--- a/include/openssl/bytestring.h
+++ b/include/openssl/bytestring.h
@@ -317,6 +317,7 @@
  * error. */
 OPENSSL_EXPORT int CBB_add_asn1_uint64(CBB *cbb, uint64_t value);
 
+
 #if defined(__cplusplus)
 }  /* extern C */
 #endif