Fix some typos on the start page
Fix some typos on the start page

Signup should be sign up
unnecessary punctuation in the ‘what you’ll need’ content

ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client