WIP: сборка английской версии mdbook

.github/prepare.sh

@@ -1,4 +1,10 @@
 #!/bin/bash
+set -e
 
-mkdir src
-cp .github/book.toml .github/*.md ./
+mkdir -p src
+cp .github/book.toml .github/*.md ./
+
+# Copy custom theme assets (language switcher, etc.)
+if [ -d ".github/theme" ]; then
+  cp -r .github/theme ./
+fi