docs: add scoring docs

[BioPhoton]

This PR includes:

• general information about scoring
• links from main docs

[github-actions]

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared current commit d74c104 with previous commit 3451929.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🟡 53	🟡 51
Code coverage	🟢 90	🟢 90	–
Security	🟡 61	🟡 61	–
Updates	🟡 74	🟡 74	–
Accessibility	🟢 92	🟢 92	–
Best Practices	🟢 100	🟢 100	–
SEO	🟡 61	🟡 61	–
Type Safety	🟢 100	🟢 100	–
Bug prevention	🟢 100	🟢 100	–
Miscellaneous	🟢 100	🟢 100	–
Code style	🟢 100	🟢 100	–
Documentation	🔴 23	🔴 23	–

👎 1 group regressed, 👍 1 audit improved, 👎 3 audits regressed, 12 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🟡 53	🟡 51

20 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	Total Blocking Time	🟥 1,660 ms	🟥 2,500 ms
Lighthouse	Speed Index	🟥 6.0 s	🟥 6.4 s
Lighthouse	Largest Contentful Paint	🟨 3.6 s	🟨 3.6 s
Lighthouse	Time to Interactive	🟥 12.9 s	🟥 13.3 s
Lighthouse	Minimizes main-thread work	🟥 10.7 s	🟥 13.0 s
Lighthouse	JavaScript execution time	🟥 4.6 s	🟥 6.0 s
Lighthouse	Uses efficient cache policy on static assets	🟨 30 resources found	🟨 30 resources found
Lighthouse	Avoids enormous network payloads	🟩 Total size was 1,943 KiB	🟩 Total size was 1,943 KiB
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Max Potential First Input Delay	🟥 1,090 ms	🟥 1,360 ms
Lighthouse	Server Backend Latencies	🟩 220 ms	🟩 120 ms
Lighthouse	Initial server response time was short	🟩 Root document took 580 ms	🟩 Root document took 520 ms
Lighthouse	Reduce unused CSS	🟥 Potential savings of 68 KiB	🟥 Potential savings of 36 KiB
Lighthouse	First Contentful Paint	🟨 2.9 s	🟨 3.0 s
Lighthouse	Network Round Trip Times	🟩 70 ms	🟩 70 ms
Code coverage	Branch coverage	🟨 85.7 %	🟨 85.7 %

589 other audits are unchanged.