Add basic repair letter

[nonprofittechy]

This adds a basic repair demand letter, based on the one from the tenant toolkit. I have toned it down slightly as the original draft immediately threatens to withhold rent. Tenants can choose 3 levels of politeness/aggression and still have option to threaten to withhold rent, but it's no longer the default.

Fix #637

See #567

In this PR, I have:

• Manually tested to ensure my PR is working
• Ensured issues that this PR closes will be automatically closed
• Requested review

[KelizaMcGuire]

@nonprofittechy This is great! I ran into a few issues while testing:

1. The colors you are trying to give the faces don't seem to be applying:

2. The interview jumped straight to the download screen, skipping the review of my answers unless I clicked Edit answers. Both of these screens skip highlighting the final two sections:

3. I think that the general day-of-the-week format is odd for the last day of contact. If it needs to be general though, maybe it should make anything other than the day of the week lowercase. It also seems like it's meant to have a name or the word you in this sentence:

4. I added a second tenant, but they don't seem to show up in the letter. Certain language might be better to include when there is more than one person requesting the work (e.g. "I" to "we"):

[nonprofittechy]

Thanks, addressed this in the latest revision. For now, I'm limiting to 1 tenant, which seems reasonable