Add instructions on how to reconcile transactions

[mxie]

Divvy works differently than Expensify in that we no longer need to create reports – we only need to edit the fields for each transaction/receipt to make sure the expense is attributed correctly. This is a process that users will have to go through regardless of whether they paid out of pocket or with a corporate card.

This content may be covered by #112 depending on how that content will be updated.

Related links

• https://help.getdivvy.com/en/articles/5491969-how-do-i-upload-receipts-in-divvy