Add solutions

exercises/007_strings2.zig

@@ -15,9 +15,9 @@ const std = @import("std");
 
 pub fn main() void {
     const lyrics =
-        Ziggy played guitar
-        Jamming good with Andrew Kelley
-        And the Spiders from Mars
+        \\Ziggy played guitar
+        \\Jamming good with Andrew Kelley
+        \\And the Spiders from Mars
     ;
 
     std.debug.print("{s}\n", .{lyrics});