introduce Batch size and a README

src/main.rs

@@ -1,5 +1,6 @@
 use std::fs;
-use serde::Deserialize;
+use std::path::Path;
+use serde::{Deserialize, Serialize};
 use reqwest::blocking::Client;
 use std::error::Error;
 
@@ -9,6 +10,7 @@ struct Config {
     access_token: String,
     visibility: String,  // Should be "unlisted"
     default_text: String,
+    batch_size: usize,
 }
 
 fn load_config() -> Result<Config, Box<dyn Error>> {
@@ -92,9 +94,9 @@ fn main() -> Result<(), Box<dyn Error>> {
     let config = load_config()?;
     let images = get_jpeg_files(&args[1]);
     let client = Client::new();
-    let total_batches = (images.len() + 19) / 20;
+    let total_batches = (images.len() + config.batch_size - 1) / config.batch_size;
 
-    for (i, chunk) in images.chunks(20).enumerate() {
+    for (i, chunk) in images.chunks(config.batch_size).enumerate() {
         upload_images_batch(&client, &config, chunk, i + 1, total_batches, &title)?;
     }