[i18n] Spell-check non-en pages other than ja and zh

[chalin]

• pt-BR - [CI][i18n] Spell check content/pt, and enable other dicts #4982
• es -- ref. Add Spanish (es) version of website pages #4887
• Add a note to the localization docs stating that spell checking should be set up if a dictionary is available for the newly proposed language - [i18n] Mention spell checker requirement for new localizations #5515