Submit version 1.3.0 to Chrome Store

Improvements
🥳 Onboarding flow improvements: Added several videos on our how to use page with specific instructions based on whether or not the extension is installed, as well as the user has signed up.

💨 Pre-header Optimizations: Some email tools allow adding several blank spaces after the email text to show only the preview text. This feature has now been added to Inboxpirates.

🔐 Security Audit: Consulted with Mukilan, to fix potential issues that may occur with authentication in the future.

Bug Fixes
👀 After signup, users were taken to a /welcome page that landed a 404. Same with the upgrade now button both of these critical bugs have now been fixed.

🐛 Loading icon, Login & Upgrade popups wouldn't close after the action buttons until the close button explicitly clicked. Now it's improved and gives a better idea to the user.

✍ Made several word usage changes to make software include lesser technical terms.

Shout out to Meenank Minnu for several feedback optimizations.