Add example

src/differ.rs

@@ -77,7 +77,7 @@ impl Differ{
     	let mut eqi: Option<usize> = None;
     	let mut eqj: Option<usize> = None;
     	for j in second_start..second_end{
-    		second_sequence_str = second_sequence.at_index(j).unwrap();  // Fix in feature
+    		second_sequence_str = second_sequence.at_index(j).unwrap();  
     		for i in first_start..first_end{
     			first_sequence_str = first_sequence.at_index(i).unwrap();
     			if first_sequence_str == second_sequence_str{ 

src/sequencematcher.rs

@@ -74,6 +74,19 @@ impl<'a> Sequence for Vec<&'a str> {
     }
 }
 
+impl<'a> Sequence for [&'a str] {
+	fn len(&self) -> usize {
+    	self.len()
+    }
+
+    fn at_index(&self, index: usize) -> Option<&str> {
+    	if index < self.len() && index >= 0 {
+    		return Some(self[index])
+    	}
+    	None
+    }
+}
+
 pub struct SequenceMatcher<'a, T: 'a + ?Sized + Sequence>{
 	first_sequence: &'a T,
 	second_sequence: &'a T,