reworked code and added ability to build slides

src/test/fs_util.rs

@@ -0,0 +1,9 @@
+use crate::app::fs_util;
+
+#[test]
+fn test_fetch_asciidoctor_paths_recursive() {
+    let paths = fs_util::fetch_paths_recursive("docs", ".adoc").unwrap();
+    let len = paths.len();
+    dbg!(paths);
+    assert_eq!(len, 4);
+}