bug: `parsers.py` can misattribute the `#audit-ignore` comment

see PR https://github.com/daisy/MathCAT/pull/728

as recently spotted by @yasumorishima, the placement `# audit-ignore` can have some misleading behaviour, as the following example is not properly recognized:
```
# audit-ignore
- name: per-fraction
tag: fraction
match:
- ...
```

but on the other hand, this works:
```
- name: per-fraction # audit-ignore
tag: fraction
match:
```

In the design of the `audit-ignore` tool, I didn't give this part much attention, but now thinking about it, placing the comment directly in front of the affected rule looks the cleanest to me.

My proposal is to implement this and document it as a best practice in the docs.

thoughts and opinions on this?