doc: contributing & security

[goulvenclech]

What does this change?

• CONTRIBUTING.md: Added.
• SECURITY.md: Added.
• crates/weblsp/README.md: Fix logos, quick links, and "Getting Started" instructions.
• crates/csslsrs/README.md: Fix logos, quick links, and "Getting Started" instructions.
• packages/csslsrs/README.md: Added logos, intro, quick links, and "Getting Started" instructions.
• packages/vscode/README.md: Added, but still work in progress.
• Private package language-server-tests-benchmarks renamed @weblsp/ls-tests-benchmarks

How is it tested?

N/A.

How is it documented?

This is documentation.

[codspeed-hq]

CodSpeed Performance Report

Merging #21 will not alter performance

_{Comparing doc-contributing-security (a08bc23) with main (ce5cdfc)}

🎉 Hooray! codspeed-node just leveled up to 3.1.1!

A heads-up, this is a breaking change and it might affect your current performance baseline a bit. But here's the exciting part - it's packed with new, cool features and promises improved result stability 🥳!
Curious about what's new? Visit our releases page to delve into all the awesome details about this new version.

Summary

✅ 10 untouched benchmarks
🆕 5 new benchmarks
⁉️ 5 dropped benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	doc-contributing-security	Change
⁉️	weblsp - Color Presentation	680.4 µs	N/A	N/A
⁉️	weblsp - Document Colors	1.7 ms	N/A	N/A
⁉️	weblsp - Document Symbols	1.1 ms	N/A	N/A
⁉️	weblsp - Folding Ranges	879.8 µs	N/A	N/A
⁉️	weblsp - Hover	2 ms	N/A	N/A
🆕	weblsp - Color Presentation	N/A	687.2 µs	N/A
🆕	weblsp - Document Colors	N/A	1.7 ms	N/A
🆕	weblsp - Document Symbols	N/A	2.2 ms	N/A
🆕	weblsp - Folding Ranges	N/A	2 ms	N/A
🆕	weblsp - Hover	N/A	869.1 µs	N/A