Syntax error in JSON Pointer

JSON Pointer provided by the Jakarta JSON Processing is designed to conform to [RFC 6901](https://tools.ietf.org/html/rfc6901).

RFC 6901 shows us the syntax of JSON Pointer as follows:
```
escaped = "~" ( "0" / "1" )
```

This means any tilde not followed by "0" or "1" is illegal and such case should be judged as a syntax error. Please note that tilde character is excluded from `unescaped` definition.

However `Json#createPointer()` in the Reference Implementation does not throw `JsonException` for the illegal input such as `/~2` and treats such tilde as a normal character.

The API Javadoc of `createPointer` says:
```
JsonException - if jsonPointer is not a valid JSON Pointer
```
This is not a request to fix the problem. I just want to know whether this is a bug or an intended behavior.

Thank you.