refactor: extract parser module with muncher and for_loops submodules from main.rs

Move Stats processing methods into dedicated parser module with separate muncher and for_loops implementations, update .gitignore to exclude test_books directory, and simplify README to remove outdated benchmark instructions

jest_rust/src/parser/for_loops.rs

@@ -0,0 +1,39 @@
+use crate::{FORBIDDEN_WORDS, stats::Stats};
+
+#[allow(dead_code)]
+/// typically 5000ms
+/// with trie this is 1600ms
+pub fn parse(stats: &mut Stats, text: &str) {
+	for sentence in text
+		.split('.')
+		.map(|s| s.trim())
+		.filter(|s| !s.is_empty())
+	{
+		stats.sentence_count += 1;
+		for word in sentence
+			.split_whitespace()
+			.map(|s| s.trim())
+			.filter(|s| !s.is_empty())
+		{
+			stats.word_count += 1;
+			//get all numbers counted
+			let mut all_capitalized = true;
+			for char in word.chars() {
+				if char.is_numeric() {
+					stats.numeric_count += 1;
+					//TODO are numbers capitalized or not? I don't know!
+				}
+				if !char.is_ascii_uppercase() {
+					all_capitalized = false;
+				}
+			}
+			if all_capitalized {
+				stats.capitalized_count += 1;
+			}
+			let lowercase_word = word.to_lowercase();
+			if FORBIDDEN_WORDS.contains(&lowercase_word) {
+				stats.forbidden_count += 1;
+			}
+		}
+	}
+}