docs: cleanup the explanation paragraphs at the start of each exercise.

exercises/variables/variables1.rs

@@ -1,6 +1,9 @@
 // variables1.rs
+//
 // Make me compile!
-// Execute `rustlings hint variables1` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables1` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE
 

exercises/variables/variables2.rs

@@ -1,5 +1,7 @@
 // variables2.rs
-// Execute `rustlings hint variables2` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables2` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE
 

exercises/variables/variables3.rs

@@ -1,5 +1,7 @@
 // variables3.rs
-// Execute `rustlings hint variables3` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables3` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE
 

exercises/variables/variables4.rs

@@ -1,5 +1,7 @@
 // variables4.rs
-// Execute `rustlings hint variables4` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables4` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE
 

exercises/variables/variables5.rs

@@ -1,5 +1,7 @@
 // variables5.rs
-// Execute `rustlings hint variables5` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables5` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE
 

exercises/variables/variables6.rs

@@ -1,5 +1,7 @@
 // variables6.rs
-// Execute `rustlings hint variables6` or use the `hint` watch subcommand for a hint.
+//
+// Execute `rustlings hint variables6` or use the `hint` watch subcommand for a
+// hint.
 
 // I AM NOT DONE