Update book.toml

added ToB in description

Author: gregotto

book.toml

@@ -4,7 +4,7 @@ language = "en"
 multilingual = false
 src = "."
 title = "Building Secure Contracts"
-description = "Follow our guidelines and best practices to write secure smart contracts."
+description = "This repository, brought to you by Trail of Bits, outlines our guidelines and best practices to write secure smart contracts."
 
 [output.html]
 git-repository-url = "https://github.com/crytic/building-secure-contracts"
@@ -15,4 +15,4 @@ no-section-label = true
 
 [output.html.fold]
 enable = true
-level = 1
+level = 1