Translator comments contains full path of the file

Comments that placed on top of each msgid contains full path to the source file.
```log
#: /Users/username/some/dir/and/my-project/src/some/module/index.njk:5
msgid "Hello"
msgstr "Hello"
```

As far as I understand this line is responsible for this behaviour:
https://github.com/alanshaw/xgettext-regex/blob/7b8aabb13e3455cf4bcae27cea4b51e01d51f2ab/index.js#L33

Instead of fullpaths can we use relative paths based on the current working directory? Something like:
```js
const relfilename = path.relative(__dirname, filename)
```
should work. What do you think?