Revert "Publish design proposals"

This reverts commit fb44e2bf48.

README.md

@@ -30,9 +30,6 @@ Before you jump into the code, review the online book [Solana: Blockchain Rebuil
 
 (The _latest_ development version of the online book is also [available here](https://solana-labs.github.io/book-edge/).)
 
-Design proposals that have not yet been integrated into the online book can be
-viewed [here](https://solana-labs.github.io/book-edge/proposals/index.html).
-
 Developing
 ===
 

ci/publish-book.sh

@@ -4,15 +4,10 @@ set -e
 cd "$(dirname "$0")/.."
 
 book/build.sh
-proposals/build.sh
 
 echo --- create book repo
 (
   set -x
-
-  test ! -d book/html/proposals
-  mv proposals/html book/html/proposals/
-
   cd book/html/
   git init .
   git config user.email "maintainers@solana.com"