LG-6120 update alt text

[nprimak]

LG-6120

What
This is the last and final subtask of LG-5774, reviewing images with empty alt tags to check if they are decorative or informative. This Figma link includes the images which were reviewed, and this translation doc includes which words were added to the yml locale files.

Testing Instructions

1. Go to localhost:3000/verify and create an account
2. While following through the steps, look out for the images in the Figma file listed as Informative
3. For those listed as informative (as you come across them), you can inspect the image with developer tools to see if the expected value shows up in the alt tag.

Copying @Danielle-Lee for content and @Kamal-Munshi for design on this PR for visibility and/or questions.

[aduth]

LGTM 👍

[aduth]

I think it's fine here since we're following an established pattern, but if we were to do the original implementation over again, I think it'd be nicer and more maintainable to structure these bullets as an array (easier to add and remove).

e.g.

start: 
  bullets: 
    - image: Email
      html: An <strong>email address</strong>
    - image: Device
      html: Enable <strong>two-step authentication</strong>.