remove unnecessary 'relativepath' warning/error case for html links

[hanbollar]

Linking

...

Problem

we were 'warn/erroring' on path links that were valid but relative, even if the file was able to load properly

Solution

allow for relative links

Breaking Change

nope

Notes

before, we're getting a lot of unnecessary warnings:

now we're no longer getting those warnings:

---

Required to Merge

• PASS - all necessary actions must pass (excluding the auto-skipped ones)
• TEST IN HEADSET - main dev-testing-example and any of the other examples still work as expected
• [ ] VIDEO - if this pr changes something visually - post a video here of it in headset-MR and/or on desktop (depending on what it affects) for the reviewer to reference.
• TITLE - make sure the pr's title is updated appropriately as it will be used to name the commit on merge
• [ ] BREAKING CHANGE
  • DOCUMENTATION: This includes any changes to html tags and their components
    • make a pr in the documentation repo that updates the manual docs to match the breaking change
    • link the pr of the documentation repo here: #pr
    • that pr must be approved by @lobau
  • SAMPLES/INDEX.HTML: This includes any changes (html tags or otherwise) that must be done to our landing page submodule as an effect of this pr's updates
    • make a pr in the mrjs landing page repo that updates the landing page to match the breaking change
    • link the pr of the landing page repo here: #pr
    • that pr must be approved by @hanbollar

[render]

Your Render PR Server URL is https://examples-mrjs-pr-665.onrender.com.

Follow its progress at https://dashboard.render.com/static/srv-cp37fsol6cac73asjh20.