Adds support for strings or maps as input to health-reasons partial

Why is this change being made?

This MR introduces a fix for the issue described here, which is a specific case that causes the site to fail to build.

The : in this string causes Hugo to convert it to a hash (or a map) which causes the call to the plainify transform to fail, which fails the build. This string is considered valid YAML, so it's not possible for linting to catch this issue.

The change made in this MR changes the health-reasons.html partial detect if the input is a string or a map and renders the contents accordingly.

Screenshot

Steps to test locally

1. Get the Handbook running locally and ensure that http://localhost:1313/handbook/engineering/infrastructure/performance-indicators/ loads correctly.

2. Update layouts/shortcodes/performance-indicators.md line 4 to pull content from 0960b7c95f867a89a22773cf17fd5ac5444e2652 instead of master. So:

   {{- $dataURL := printf "https://gitlab.com/gitlab-com/www-gitlab-com/-/raw/0960b7c95f867a89a22773cf17fd5ac5444e2652/data/performance_indicators/%s.yml" (.Get 0) }}

3. Delete the cache and rerun the build (for example: rm -rf public/ && hugo server). This should produce the error Error: error building site: render: failed to render pages: render of "section" failed

4. Checkout this branch string-or-maps-health-reasons and rerun the build (rm -rf public/ && hugo server). It should complete without errors and the http://localhost:1313/handbook/engineering/infrastructure/performance-indicators/ page should load as expected.

Author and Reviewer Checklist

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Commits

• Adds support for strings or maps as input to health-reasons partial

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