chore(macros/LearnSidebar): add Japanese translation for 4 locations

[gurezo]

Summary

@hmatrjp @potappo , mdn-yari-ja

please review for this pull request

• issue: サイドメニュー の翻訳（４箇所） #760

Problem

still en-us only

English pages

• Performance — Making websites fast and responsive
• Performance guides
• Further resources
• Common questions
• cf. https://developer.mozilla.org/en-US/docs/Learn/Common_questions

Japanese pages

• パフォーマンス — ウェブサイトを高速かつ応答性の高いものにする
• パフォーマンスガイド
• その他のリソース
• よくある質問

English pages	Japanese pages

Solution

translate japanese for LearnSidebar.ejs

NOTICE

@caugner, @wbamberg , @schalkneethling

Please merge once mdn-yari-ja is approved.

Before

still en-us only

After

add tranlate japanese for LearnSidebar.ejs

[gurezo]

@caugner, @wbamberg , @schalkneethling

already approved by mdn-yari-ja (@potappo) please this PR review

[caugner]

Thanks @gurezo!

PS: In the future, I recommend to mention @mdn/core-dev only, because a review from this team is required for the merge.

[gurezo]

Hi @caugner thanks for reprely, ok next time i will send @mdn/core-dev team!