feat: use improved watcher/rebuilder script

Please see [1] for the discussion and [2] for the code review.

[1] https://discussion.fedoraproject.org/t/improved-build-script-for-doc-repos-with-change-detection/40920/10
[2] https://pagure.io/neuro-sig/documentation/pull-request/23

preview.sh

@@ -1,18 +1,3 @@
-#!/bin/sh
+#!/bin/bash
 
-if [ "$(uname)" = "Darwin" ]; then
-    # Running on macOS.
-    # Let's assume that the user has the Docker CE installed
-    # which doesn't require a root password.
-    echo "The preview will be available at http://localhost:8080/"
-    docker run --rm -v "$(pwd):/antora:ro" -v "$(pwd)/nginx.conf:/etc/nginx/conf.d/default.conf:ro" -p 8080:80 nginx
-
-elif [ "$(expr substr "$(uname -s)" 1 5)" = "Linux" ]; then
-    # Running on Linux.
-    # Fedora Workstation has python3 installed as a default, so using that
-    echo ""
-    echo "The preview is available at http://localhost:8080"
-    echo ""
-    cd ./public
-    python3 -m http.server 8080
-fi
+echo "Deprecated. Use the builder.sh script instead"