Handbook references to availability SLA dashboard defaults to current month to date view

Why is this change being made?

Multiple availability dashboards are referred to in the handbook which causes confusion for team members trying to find an authoritative source. The reason for multiple links is because they represent different time frame views. This change intents to point team members consistently to the month to date view initially. They can then explore the required timeframes themselves without wondering why the links provided in the handbook are different.

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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