add build workflow

.github/scripts/commit-repo.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -e
+
+rsync -a --delete --exclude .git --exclude .gitignore ../master/repo/ .
+git config --global user.email "github-actions[bot]@users.noreply.github.com"
+git config --global user.name "github-actions[bot]"
+git status
+if [ -n "$(git status --porcelain)" ]; then
+    git add .
+    git commit -m "Update extensions repo"
+    git push
+else
+    echo "No changes to commit"
+fi

.github/scripts/create-repo.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+mkdir -p repo/
+
+cp -f server/build/server-1.0-all.jar repo/