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muncher and for_loops implementations, update .gitignore to exclude test_books directory, and simplify README to remove outdated benchmark instructions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/muncher.rs

@@ -0,0 +1,66 @@
+use crate::{FORBIDDEN_WORDS, stats::Stats};
+
+#[allow(dead_code)]
+/// probably buggy. for example, are new lines sentences? what if the text has no last period?
+/// 500ms is without forbidden words check, but...
+/// 6000ms if adding forbidden words.. so not faster
+/// with trie this is 2600ms
+pub fn parse(stats: &mut Stats, text: &str) {
+	let mut capitalized = true;
+	let mut whitespaced = false;
+	let mut dotted = false;
+	let mut word = String::new();
+	for char in text.chars() {
+		if whitespaced {
+			if !char.is_whitespace() {
+				whitespaced = false; //end whiteness
+			}
+			continue;
+		} else if char.is_whitespace() {
+			whitespaced = true;
+			stats.word_count += 1; //end of word
+			if capitalized {
+				stats.capitalized_count += 1;
+			} else {
+				//reset capitalized word
+				capitalized = true;
+			}
+			let lowercase_word = word.to_lowercase();
+			if FORBIDDEN_WORDS.contains(&lowercase_word) {
+				stats.forbidden_count += 1;
+			}
+			word = String::new();
+			continue;
+		}
+		if dotted {
+			if char != '.' {
+				dotted = false; //end sentencing
+			}
+			continue;
+		} else if char == '.' {
+			dotted = true;
+			stats.sentence_count += 1;
+			stats.word_count += 1; //end of word
+			if capitalized {
+				stats.capitalized_count += 1;
+			} else {
+				//reset capitalized word
+				capitalized = true;
+			}
+			let lowercase_word = word.to_lowercase();
+			if FORBIDDEN_WORDS.contains(&lowercase_word) {
+				stats.forbidden_count += 1;
+			}
+			word = String::new();
+			continue;
+		}
+		word += &char.to_string();
+		if char.is_numeric() {
+			stats.numeric_count += 1;
+			capitalized = false;
+		}
+		if !char.is_ascii_uppercase() {
+			capitalized = false;
+		}
+	}
+}