add logo guideline

[taisuou]

Description:

add logo guideline.
add png,svg logo file.

Types of changes:

• Bug fix [type/bug]
• New feature [type/feature]
• Add tests [type/test]
• Security related changes [type/security]
• Add documents [type/documentation]
• Refactoring [type/refactoring]
• Update dependencies [type/dependency]
• Update benchmarks and performances [type/bench]
• Update CI [type/ci]

Changes to Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you successfully ran tests with your changes locally?

Checklist:

• I have read the CONTRIBUTING document.
• I have checked open Pull Requests for the similar feature or fixes?
• I have added tests and benchmarks to cover my changes.
• I have ensured all new and existing tests passed.
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly.

[vdaas-ci]

[CHATOPS:HELP] ChatOps commands.

• 🙆‍♀️ /approve - approve
• 💌 /changelog - add changelog comment
• 🍱 /format - format codes and add licenses
• ✅ /gen-test - generate test codes
• 🏷️ /label - add labels
• ⏪ /rebase - rebase master
• 🔚 2️⃣ 🔚 /label actions/e2e-deploy - run E2E deploy & integration test

[kpango]

I couldn't agree with this design, so could you please use the old image for README.md until we can create a dark-mode compatible svg image?

I think current design seems cool, but I understand that violation of the new guidelines.

[taisuou]

I'm sorry for late replay.

in this case, let's keep current design.
I once added media query css for readme.svg.

<style type="text/css"> .st0{fill:#303030;} .st1{fill:url(#SVGID_1_);} .st2{fill:url(#SVGID_2_);} .st3{fill:url(#SVGID_3_);} .st4{fill:url(#SVGID_4_);} @media (prefers-color-scheme: dark) { .st0{fill:#ffffff;} .st1{fill:#ffffff;} .st2{fill:#ffffff;} .st3{fill:#ffffff;} .st4{fill:#ffffff;} } </style>

it seemed good but in this case below, it doesn,t works.
When github browser setting is light against system darktheme setting,
svg media query make logo white.

for now, I have no idea to change color and mono logo...