Add a landing page before redirecting to Freshbooks

[chasenlehara]

As a user, it’s jarring to go to the domain and immediately be redirected to Freshbooks without any notice or context of what to expect.

Some ideas:

• When a user first goes to the page, they should see a brief description of what the app does and why it needs permissions from Freshbooks
• The user should be able to click a link to go to Freshbooks and authorize the app

[christopherjbaker]

Partially resolved, in that it doesn't automatically redirect. It does not explain anything though.