1.20 update

Adds an optional feature which displays the contents of a bookshelf when left-clicked. Sneaking must be used to destroy the bookshelf when enabled.
Updates depreciated sign code.
Bumps the API version to 1.20
Builds against 1.20

src/main/resources/plugin.yml

@@ -1,7 +1,7 @@
 name: BooksWithoutBorders
 version: '${project.version}'
 main: net.knarcraft.bookswithoutborders.BooksWithoutBorders
-api-version: 1.18
+api-version: 1.20
 prefix: Books Without Borders
 authors: [ EpicKnarvik97, AkiraAkiba ]
 description: A continuation of the original Books Without Borders
@@ -131,6 +131,7 @@ permissions:
       bookswithoutborders.save: true
       bookswithoutborders.load: true
       bookswithoutborders.delete: true
+      bookswithoutborders.peekbookshelf: true
   bookswithoutborders.alterbooks:
     description: Allows player to change books' data such as lore/title/author/generation/formatting and unsigning books
     children:
@@ -190,4 +191,6 @@ permissions:
   bookswithoutborders.reload:
     description: Allows player to reload this plugin
   bookswithoutborders.setgeneration:
-    description: Allows player to change the generation of a book (Original, Copy, Copy of Copy)
+    description: Allows player to change the generation of a book (Original, Copy, Copy of Copy)
+  bookswithoutborders.peekbookshelf:
+    description: Allows player to left-click a bookshelf to see the contents of the shelf