Draft: Adding dialog around workflow processes

Why is this change being made?

From a discussion around how to improve our workflow processes, the intention of this MR is to update our handbook to provide better clarity around when issues are in workflow states, milestones shouldn't be set as well as when they are in blocked states, they shouldn't be in milestones until blockers are removed.

Author Checklist

• 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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  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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