### Godot version

3b086aa06

### System information

ArchLinux x11

### Issue description

```gdscript
extends Node

@export_group("My Properties")
@export var number = 3
@export var string = ""

@export_group("Prefixed Properties", "prefix_")
@export var prefix_number = 3
@export var prefix_string = ""

@export_group("", "")
@export var ungrouped_number = 3
```

![image](https://user-images.githubusercontent.com/70787919/214983963-528c415b-745b-47fc-9777-36ebe31a3060.png)


### Steps to reproduce

- create script
- @export_group
- go inspector

### Minimal reproduction project

‮
return tokenizer.get_comments().has(p_line);
}
String GDScriptParser::get_doc_comment(int p_line, bool p_single_line) {
	const HashMap<int, GDScriptTokenizer::CommentData> &comments = tokenizer.get_comments();
	ERR_FAIL_COND_V(!comments.has(p_line), String());
	if (p_single_line) {
		if (comments[p_line].comment.begins_with("##")) {
			return comments[p_line].comment.trim_prefix("##").strip_edges();
		}
		return "";
	}
	String doc;
	int line = p_line;
	bool in_codeblock = false;
	while (comments.has(line - 1)) {
		if (!comments[line - 1].new_line || !comments[line - 1].comment.begins_with("##")) {
			break;
		}
		line--;
	}
	int codeblock_begins = 0;
	while (comments.has(line)) {
		if (!comments[line].new_line || !comments[line].comment.begins_with("##")) {