### Godot version

v4.0.stable.official [92bee43ad]

### System information

Steam OS Holo, Steam Deck

### Issue description

Using a `[br]` tag at the end of a line in a documentation comment adds an additional space at the beginning of the following line:

![image](https://user-images.githubusercontent.com/857660/236700815-c78a317f-cdf8-4f3c-8489-41f9559ffe6d.png)


### Steps to reproduce

The script below is what I used to generate the image above:

```gdscript
class_name Test
extends Node

## High-level description
##
## First line of detail.[br]
## Second line of detail.
```

Removing the space between `##` and `Second` doesn't change the output.

The only workaround I've found so far is to remove the linebreak after the `[br]` tag, but this makes the documentation comments harder to read in the editor:

```gdscript
class_name Test
extends Node

## High-level description
##
## First line of detail.[br]Second line of detail.
```

### Minimal reproduction project

N/A
}
				if (colon_pos == stripped_line.length() || stripped_line[colon_pos++] != ':') {
					continue; 
				}
				title = stripped_line.substr(open_bracket_pos, close_bracket_pos - open_bracket_pos).strip_edges();
				link = stripped_line.substr(colon_pos).strip_edges();
			}
			mode = TUTORIALS;
			in_codeblock = false;
		} else if (stripped_line.is_empty()) {
			continue;
		} else {
			
			if (mode == TUTORIALS) {
				mode = DONE;
			}
			in_codeblock = _in_codeblock(doc_line, in_codeblock, &codeblock_begins);
		}
		if (in_codeblock) {
			int i = 0;
			for (; i < codeblock_begins; i++) {
				if (doc_line[i] != ' ') {
					break;
				}
			}
			doc_line = doc_line.substr(i);
		} else {
			doc_line = stripped_line;
		}
		String line_join = (in_codeblock) ? "\n" : " ";