Rename buffer crate to text and name its entrypoint after the crate

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/text/src/random_char_iter.rs

@@ -0,0 +1,28 @@
+use rand::prelude::*;
+
+pub struct RandomCharIter<T: Rng>(T);
+
+impl<T: Rng> RandomCharIter<T> {
+    pub fn new(rng: T) -> Self {
+        Self(rng)
+    }
+}
+
+impl<T: Rng> Iterator for RandomCharIter<T> {
+    type Item = char;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.0.gen_range(0..100) {
+            // whitespace
+            0..=19 => [' ', '\n', '\t'].choose(&mut self.0).copied(),
+            // two-byte greek letters
+            20..=32 => char::from_u32(self.0.gen_range(('α' as u32)..('ω' as u32 + 1))),
+            // three-byte characters
+            33..=45 => ['✋', '✅', '❌', '❎', '⭐'].choose(&mut self.0).copied(),
+            // four-byte characters
+            46..=58 => ['🍐', '🏀', '🍗', '🎉'].choose(&mut self.0).copied(),
+            // ascii letters
+            _ => Some(self.0.gen_range(b'a'..b'z' + 1).into()),
+        }
+    }
+}