Create an addon badge for addon tier features

Why is this change being made?

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From discussion in Slack and in this issue, we need to update the release post badges on the gitlab tiers such to display when a given feature is an add-on.

This MR attempts to update the badges to include an optional add-on badge through the addition of an attribute in release post entry yaml files.

The add_ons attribute is an optional array of add on names.

The result as shown in the following screenshot:

Single

Double

Many

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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Commits

• Create an addon badge for addon tier features

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