Fix spacing on lesson duration table

[ehumph]

The word "minutes" ended up on a line by itself at the very end of the table. This restores the proper spacing

[github-actions[bot]]

No broken urls! :tada: Comment updated at 2023-07-21 with changes from c807a515a7cb196187f3ed80a6941e304d3a5248

[github-actions[bot]]

No spelling errors! :tada: Comment updated at 2023-07-21 with changes from c807a515a7cb196187f3ed80a6941e304d3a5248

[github-actions[bot]]

Re-rendered previews from the latest commit:

• See preview of Bookdown here
• See preview of Coursera/Leanpub version here
• Download the preview of .docx file

Updated at 2023-07-21 with changes from c807a515a7cb196187f3ed80a6941e304d3a5248