* Create vi.ts
Create i18n Vietnamese translation file.
* Update translation.ts
Added Vietnamese language support.
* Update config.ts
Add Vietnamese (vi) to be a possible value for the `lang` key.
* Create README.vi.md
Created Vietnamese version of README.
* Update README.md
Added navigation/link to Vietnamese version of README.
* Update README.md
fixed a mistake
* Create th.ts
Created i18n Thai translation file.
* Update translation.ts
Added Thai language support.
* Update config.ts
Added Spanish (es) and Thai (th) to commented possible values for `lang` key.
* Create README.th.md
Created Thai version of README.
* Update README.md
Added navigation/link to Thai version of README.
* Create es.ts
Added Spanish translation for site content and interface elements.
* Update translation.ts
Added Spanish (es) translation support to the language configuration.