refactor

src/blacklist.rs

@@ -1,3 +1,7 @@
+/// Checks if a domain is present in the blacklist of unwanted domains.
+///
+/// This function checks the `$BLACKLIST_DOMAINS` environment variable for a comma-separated list of regular expressions to match against.
+/// If a match is found, it immediately returns `true`. Otherwise, it returns `false`.
 pub fn check_blacklist(domain: &str) -> bool {
     let blacklist_raw = std::env::var("BLACKLIST_DOMAINS").unwrap_or_default();