Don't Open Login and Signup Links in a New Window on Checkly Site

When visiting the Checkly site, existing users don't need to have the Checkly homepage persist in its own tab when clicking Login. They're already dedicated users. If they aren't, it would be best to sustain the history and enable quicker navigation backward.

Likewise, there's no clear utility for prospective customers to have a new tab when clicking Start for Free. They're entering lower funnel, and the vestigial tab only serves to frustrate and break the navigation history.

Some considerations from GPT: https://chat.openai.com/share/fc9e7f91-c21c-4fab-84a6-63bfc873bc81