lychee.toml carries stale awesome-student-resources cruft

[yakew7]

Problem

lychee.toml was copied from the sibling repo and still contains:

• An exclude entry for https://www.autodesk.com/education/edu-software/overview, a URL that doesn't appear anywhere in this repo's README
• A comment listing bot-blocking domains (inkscape.org, autodesk.com, etc.) that are specific to the sibling's Student Discounts / FOSS Picks sections and don't apply to this repo's content

Dead config like this makes the file misleading for anyone trying to understand why a given accept/exclude rule exists here.

What to do

• Remove the autodesk.com exclude entry (not used in this repo)
• Trim the top comment down to only the domains actually present in this repo's README that are known to 403 automated requests (e.g. kaptest.com, sparknotes.com, feynmanlectures.caltech.edu, ibdocuments.com, quizlet.com)
• Re-run the dead-link check locally to confirm nothing regresses

Acceptance criteria

• No exclude/comment entries reference domains absent from this repo's content
• lychee --config lychee.toml --no-progress README.md CONTRIBUTING.md CODE_OF_CONDUCT.md CHANGELOG.md still passes

Scope: small, roughly 15 minutes. Good first issue.