• Added translation of Installation page
  • add React to an existing project and React Developer Tools phrases were translated similar to existing pages of the same name
  • Next Steps was translated similar to the one in Quick Start - Подальші кроки. Although it can be changed to Наступні кроки or Далі in both pages.

Also:

• some excessive use of your was omitted as it's unnatural in Ukrainian
• to get a taste of was translated as ознайомитися з, 'cause I didn't find if it's okay to use word-by-word translation for this idiom
• Fork as name button was left untouched until we translate common UI words including ones for sandbox
• non-breakable space was not used before the dash, but I think, that we want such rule in project, as I've already encountered issue with dash being on new line.