Documentation issue: clarify that a relative path is required.

[syntaxfiend]

Thanks for making this, seems quite useful! One small nitpick though.

The docs say that a full absolute path is required. But if i give it a full absolute path
/path/to/my/vault/meta/changelog.md it errors.
It should be stated that it wants a relative path within the vault, like this.
meta/changelog.md

[philoserf]

I have a gist of a rewrite improving the text for this (and more).

https://gist.github.com/philoserf/f70c9629251a1425802675e12bd222b6