change "Guidance" to "How to"

[dmvancura]

Who discovered this?

deana

What happened?

it still says Guidance

Environment

production

What pages did this appear on?

https://beta.notify.gov/using-notify/guidance

Detail the steps for someone to reproduce

change "Guidance" to "How to" on H1 and side nav

What browsers are you seeing the problem on?

Chrome

Relevant log output