[WIP] add error_squiggle gem

```
$ ./local/bin/ruby -e '1.time {}'
-e:1:in `<main>': undefined method `time' for 1:Integer (NoMethodError)

1.time {}
 ^^^^^
Did you mean?  times
```

https://bugs.ruby-lang.org/issues/17930

test/ruby/test_name_error.rb

@@ -151,6 +151,6 @@ class TestNameError < Test::Unit::TestCase
     error = assert_raise(NameError) do
       receiver::FOO
     end
-    assert_equal "uninitialized constant #{'A' * 120}::FOO", error.message
+    assert_match /\Auninitialized constant #{'A' * 120}::FOO$/, error.message
   end
 end