Fix append to DOM

[dnicolson]

Description

This pull request delays appending to the DOM until after the ytd-update-grid-state-action event is dispatched.

Motivation and Context

Recent changes have resulted in some elements being unavailable on the DOMContentLoaded event.

How Has This Been Tested?

Manually in Chrome with a custom YouTube playlist.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[codecov-commenter]

Codecov Report

Merging #143 (58b2177) into master (3001009) will not change coverage. The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #143   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            8         8           
  Lines           52        52           
  Branches         7         7           
=========================================
  Hits            52        52           

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update d7593bc...58b2177. Read the comment docs.

[avallete]

:tada: This PR is included in version 1.5.6 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: