fix: rename option to options

exercises/options/README.md

@@ -1,4 +1,4 @@
-# Option
+# Options
 
 Type Option represents an optional value: every Option is either Some and contains a value, or None, and does not. 
 Option types are very common in Rust code, as they have a number of uses:

exercises/options/options1.rs

@@ -1,5 +1,5 @@
-// option1.rs
-// Make me compile! Execute `rustlings hint option1` for hints
+// options1.rs
+// Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
 // I AM NOT DONE
 

exercises/options/options2.rs

@@ -1,4 +1,4 @@
-// option2.rs
+// options2.rs
 // Make me compile! Execute `rustlings hint option2` for hints
 
 // I AM NOT DONE

exercises/options/options3.rs

@@ -1,4 +1,4 @@
-// option3.rs
+// options3.rs
 // Make me compile! Execute `rustlings hint option3` for hints
 
 // I AM NOT DONE