added a script to check for dupe comments

scripts/check_dupes.rs

@@ -0,0 +1,34 @@
+use std::{collections::HashMap, fs};
+use serde_json::Value;
+
+fn main() {
+  let comments: Vec<Value> =
+    serde_json::from_str(&fs::read_to_string("docs/comments.json").unwrap()).unwrap();
+  let mut seen: HashMap<(String, String, i64), usize> = HashMap::new();
+  let mut dupes = 0;
+  for (i, c) in comments.iter().enumerate() {
+    let k = (
+      c["id"].as_str().unwrap_or("").into(),
+      c["text"].as_str().unwrap_or("").into(),
+      c["timestamp"].as_i64().unwrap_or(0),
+    );
+    
+    if let Some(&first) = seen.get(&k) {
+      dupes += 1;
+      println!(
+        "  Index {} dupes index {} | id={} | ts={} | text={:.80}",
+        i, first, k.0, k.2, k.1
+      );
+    } else {
+      seen.insert(k, i);
+    }
+  }
+  println!(
+    "{}",
+    if dupes > 0 {
+      format!("Found {} duplicate(s)", dupes)
+    } else {
+      format!("No duplicates among {} comments.", comments.len())
+    }
+  );
+}