Pre-Submission Checklist

• Your pull request targets the staging branch of freeCodeCamp.
• Branch starts with either fix/, feature/, or translate/ (e.g. fix/signin-issue)
• You have only one commit (if not, squash them into one commit).
• All new and existing tests pass the command npm test. Use git commit --amend to amend any fixes.

Type of Change

• Small bug fix (non-breaking change which fixes an issue)

Checklist:

• Tested changes locally.
• Closes currently open issue (replace XXXX with an issue no): Closes [Beta] Remove CSS, Fix Sequencing Issues in Basic HTML & HTML5 Section #12688 and Closes [beta] Basic HTML - challenge "Add Images to your Website" feels out of place #12659

Description

• Removes all CSS in seed code and one reference to CSS that was in a challenge's text (adjusts the translations, too)
• Adds an <hr> to delineate instructions part of challenge copy per this comment
• Carries a main tag that's introduced with a new challenge through the seed code
• Fixed one test in Turn an Image into a Link challenge to remove the class name reference
• Makes a re-order edit as suggested in [beta] Basic HTML - challenge "Add Images to your Website" feels out of place #12659 and also moves the Introduction to HTML5 Elements challenge back a bit to flow more logically with the other challenges
• for good measure, changes "Free Code Camp" to "freeCodeCamp" 😄