Intro to HTML and CSS, Working with Text: Removed timestamps in links

[nwmason]

Because

The YouTube links for Kevin Powell's videos linked in the HTML Foundations section, "Intro to HTML and CSS" and "Work with Text", had timestamps within the link, starting each video in the middle rather than the beginning.

This PR

• Deleted timestamp from one YouTube link in html-boilerplate.md
• Deleted timestamp from two YouTube links in working-with-text.md

Issue

No related issue, this is a simple change that bothered me enough to fix it.

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[MaoShizhong]

Thanks for the PR. Will close this one as the time skips were added to skip past any introduction and promos. The links all start at the point where the actual video content begins.