moved gen-wallpapers to its own crate, outputing json to stdout

crates/gen-wallpapers/examples/cli.rs

@@ -0,0 +1,31 @@
+use clap::Parser;
+use gen_wallpapers::MetadataList;
+use std::fs::read_dir;
+use std::path::PathBuf;
+
+#[derive(Parser)]
+struct Cli {
+    folder: PathBuf,
+}
+
+fn main() {
+    let cli = Cli::parse();
+    let dir = match read_dir(cli.folder) {
+        Ok(dir) => dir,
+        Err(e) => {
+            eprintln!("failed to read folder: {e}");
+            return;
+        }
+    };
+
+    let metadata = MetadataList::process_folder(dir, true);
+
+    let json = match metadata.to_json() {
+        Ok(json) => json,
+        Err(e) => {
+            eprintln!("failed to serialize json: {e}");
+            return;
+        }
+    };
+    println!("{json}");
+}