Results 7 issues of CoinEZ

ja: tooling check (google#652)

- `mdbook serve` does NOT reflect translations in the following areas in both localhost and prod ![Screenshot 2023-05-30 at 20 27 23](https://github.com/google/comprehensive-rust/assets/132030351/84d9c7e5-7195-4384-96af-4539fc9ef742) - same behavior as above observed in prod...

Mainly course infrastructure Translated "Deep Dive" to 〇〇「編」 For #652.

Sections 0, 1, 2, and 3 - embedded playground = 組み込まれたプレイグラウンド(?) - NOTE: Ch2.3 "With this in place, follow these steps to build a Rust binary from one of the...

short chapter, did not separate to sections Translation not reflected on Ch.3.0: "They should ask questions ... you are free to skip them as you like. "

・"C/C++/Java tradition" -> 「C/C++/Java系統」: could not think of anything better ・"# Small Example" left untranslated

#652 Have added a few comments on individual commits. Please let me know if you prefer them all here instead.

translation
translation/ja