Markdownlint rules: test output formatters

Capturing discussion from https://gitlab.slack.com/archives/C81PT2ALD/p1690991985286309 as it contains some work Marcel identified as potentially useful, but hadn't made an issue for yet:

@marcel.amirault: I'd also recommend turning on these rules one at a time. Clean up the ordered list style and turn on the ordered list rule in one MR, then unordered list style and unordered list rule in another MR, etc. It keeps it much more manageable, and easier to review. If you need any help with this, let me know, it was a big effort when we did it over in the docs
@eread: I wonder what "strict": false, does to the line-length rule
Marcel: Oh, I see that the rule allows for long links now, looking for the first whitespace after 120 characters, not the first character: https://github.com/markdownlint/markdownlint/blob/main/docs/RULES.md#md013---line-length, so that's great to know! You can also disable for tables, nice. Where do you see the strict parameter?
Evan: At https://gitlab.slack.com/archives/C81PT2ALD/p1690991998106119?thread_ts=1690991985.286309&cid=C81PT2ALD
```
"line-length": {
  "strict": false,
  "line_length": 120,
  "code_blocks": false
},
```
Marcel: Whoops, totally skimmed right past that. I reminds me that I need to test the new output formatters. I've been aware of it for a while (have a todo about it somewhere), just haven't had the chance to test it on the main docs. Here are the details for strict: https://github.com/DavidAnson/markdownlint/blob/main/doc/md013.md strict: false seems to be the default already, so probably don't actually need it in the config (but doesn't hurt either)