add upgrade document

[vankichi]

Description:

SSIA

Related Issue:

How Has This Been Tested?:

Environment:

• Go Version: 1.18.3
• Docker Version: 20.10.8
• Kubernetes Version: 1.22.0
• NGT Version: 1.14.7

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 - replace the PR body by changelog details
• 🍱 /format - format codes and add licenses
• ✅ /gen-test - generate test codes
• 🏷️ /label - add labels
• ⏪ /rebase - rebase main
• 🔚 2️⃣ 🔚 /label actions/e2e-deploy - run E2E deploy & integration test

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Pages

Latest commit:	b8c355f
Status:	✅  Deploy successful!
Preview URL:	https://d0c71d4c.vald.pages.dev
Branch Preview URL:	https://documentation-docs-add-upgra.vald.pages.dev

View logs

[github-actions]

[LanguageTool] _{reported by reviewdog 🐶}
Possible typo: you repeated a word (ENGLISH_WORD_REPEAT_RULE)
Suggestions: vald
Rule: https://community.languagetool.org/rule/show/ENGLISH_WORD_REPEAT_RULE?lang=en-US
Category: MISC

[github-actions]

[LanguageTool] _{reported by reviewdog 🐶}
Possible typo: you repeated a word (ENGLISH_WORD_REPEAT_RULE)
Suggestions: vald
Rule: https://community.languagetool.org/rule/show/ENGLISH_WORD_REPEAT_RULE?lang=en-US
Category: MISC

[github-actions]

[LanguageTool] _{reported by reviewdog 🐶}
This sentence does not start with an uppercase letter. (UPPERCASE_SENTENCE_START)
Suggestions: Spec
Rule: https://community.languagetool.org/rule/show/UPPERCASE_SENTENCE_START?lang=en-US
Category: CASING

[github-actions]

[LanguageTool] _{reported by reviewdog 🐶}
This sentence does not start with an uppercase letter. (UPPERCASE_SENTENCE_START)
Suggestions: Image
Rule: https://community.languagetool.org/rule/show/UPPERCASE_SENTENCE_START?lang=en-US
Category: CASING

[kpango]

LGTM