fix(readme): usage section

tensorush · tensorush · commit f91b8e06eea9 · 2024-07-16T19:35:13.000+03:00
diff --git a/README.md b/README.md
@@ -21,7 +21,7 @@ const cfitsio_dep = b.dependency("cfitsio", .{
     .optimize = optimize,
 });
 const cfitsio_mod = cfitsio_dep.module("cfitsio");
-<compile>.root_module.addImport("cfitsio", cfitsio_mod);;
+<compile>.root_module.addImport("cfitsio", cfitsio_mod);
 ```
 
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