Update toctree_en.rst

[speco29]

Summary

Correcting the title of english lecture, which was written is spanish. issue #351

Checklist

• [x] Variables, functions and comments are translated to Spanish
• [x] Functions follow underscore notation
• [x] Spell check done & typos fixed
• [x] All python code is PEP8 compliant
• [x] Test coverage with Playwright implemented; locators are Pyhton code
• [x] Reviewers assigned (all peers & at least 1 mentor)

Screenshots

(prefer Playwright recorded video or animated gif)