### Godot version

4.0 stable

### System information

Fedora, RX 590

### Issue description

I made a dictionary, and instead of using `:` to separate between key and value, i accidentally used `=`.
The error message was not clear at all `Parse Error: Expected identifier or string as LUA-style dictionary key.` 

I don't think assuming that people know how dictionaries are made in LUA is reasonable. And if this is not about LUA the programming language, i don't even know what this is about :D

I think this error should be replaced with something of the sort "Please use `:` as separator instead of `=` in your dictionary"

### Steps to reproduce

Paste this code in a script:

```

var dict = {
	1 = "lala"
}
```

Observe the error message
![image](https://user-images.githubusercontent.com/7917475/224549538-38ea25aa-ba75-431e-868b-0733a53b90ad.png)


### Minimal reproduction project

see above
const HashMap<int, GDScriptTokenizer::CommentData> &comments = tokenizer.get_comments();
	if (!comments.has(p_line)) {
		return;
	}
	ERR_FAIL_COND(!p_brief.is_empty() || !p_desc.is_empty() || p_tutorials.size() != 0);
	int line = p_line;
	DocLineState state = DOC_LINE_NORMAL;
	enum Mode {
		BRIEF,
		DESC,
		TUTORIALS,
		DONE,
	};
	Mode mode = BRIEF;
	if (p_inner_class) {
		while (comments.has(line - 1)) {
			if (!comments[line - 1].new_line || !comments[line - 1].comment.begins_with("##")) {
				break;
			}
			line--;
		}
	}
	String space_prefix;
	if (comments.has(line) && comments[line].comment.begins_with("##")) {
		int i = 2;
		for (; i < comments[line].comment.length(); i++) {
			if (comments[line].comment[i] != ' ') {
				break;
			}