sudo apt-get update と upgrade の違いとは？ (#560)

* posteditor修正

* 導入部の翻訳

* translate What Are the Differences Between sudo apt-get update and sudo apt-get upgrade?

* translate How to Use the sudo apt-get update Command

* translate How to Use Special Options With the sudo apt-get upgrade Command

* complete translation 1st version

* 音読後の微修正対応

* Apply suggestions from code review

Co-authored-by: yoko <[email protected]>

---------

Co-authored-by: yoko <[email protected]>