Update language to handbook about expenses

Why is this change being made?

Transparency regarding values and the use of company money to ensure team members understand the outcome if fraudulent charges or expenses are submitted or discovered via an audit. @rschulman @jhurewitz @sunghaekim I have been working with @emilyplotkin regarding expenses and team members. Based on that conversation I wanted to make an update to the handbook.

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Does this MR meet the acceptance criteria?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what