test: add custom matcher for markdown table rows

[hanna-skryl]

Closes #757

This PR introduces a custom matcher, toContainMarkdownTableRow, designed to validate the presence of specific rows within Markdown tables during testing.

[github-actions]

Code PushUp

😟 Code PushUp report has regressed – compared target commit 2628fac with source commit ec834db.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🟡 54	🟡 53
Code coverage	🟢 91	🟢 91
Security	🟡 79	🟡 79	–
Updates	🟡 77	🟡 77	–
Accessibility	🟢 92	🟢 92	–
Best Practices	🟢 100	🟢 100	–
SEO	🟡 61	🟡 61	–
Bug prevention	🟢 100	🟢 100	–
Code style	🟢 100	🟢 100	–
Documentation	🔴 23	🔴 23	–

👎 2 groups regressed, 👎 5 audits regressed, 13 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🟡 54	🟡 53
Code coverage	Code coverage metrics	🟢 91	🟢 91

16 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	Largest Contentful Paint	🟨 3.4 s	🟨 3.5 s
Lighthouse	Time to Interactive	🟥 13.6 s	🟥 14.6 s
Lighthouse	Total Blocking Time	🟥 2,960 ms	🟥 4,210 ms
Lighthouse	First Contentful Paint	🟨 2.7 s	🟨 2.7 s
Code coverage	Line coverage	🟩 90.1 %	🟩 90.1 %
Lighthouse	Minimizes main-thread work	🟥 13.0 s	🟥 14.8 s
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	JavaScript execution time	🟥 6.2 s	🟥 7.1 s
Lighthouse	Uses efficient cache policy on static assets	🟨 27 resources found	🟨 27 resources found
Lighthouse	Avoids enormous network payloads	🟩 Total size was 1,818 KiB	🟩 Total size was 1,818 KiB
Lighthouse	Initial server response time was short	🟩 Root document took 510 ms	🟩 Root document took 450 ms
Lighthouse	Max Potential First Input Delay	🟥 1,830 ms	🟥 1,770 ms
Lighthouse	Server Backend Latencies	🟩 150 ms	🟩 200 ms
Lighthouse	Eliminate render-blocking resources	🟥 Potential savings of 820 ms	🟥 Potential savings of 810 ms
Lighthouse	Network Round Trip Times	🟩 20 ms	🟩 20 ms
Lighthouse	Speed Index	🟨 5.4 s	🟨 5.4 s
Lighthouse	Avoid large layout shifts	🟩 0	🟩 1 layout shift found
Lighthouse	Cumulative Layout Shift	🟩 0	🟩 0

578 other audits are unchanged.

[matejchalk]

This looks so much nicer to use 👍