feat(locale): add Estonian language (#3036)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/runtime/locale/index.ts

@@ -3,6 +3,7 @@ export { default as cs } from './cs'
 export { default as da } from './da'
 export { default as de } from './de'
 export { default as el } from './el'
+export { default as et } from './et'
 export { default as en } from './en'
 export { default as es } from './es'
 export { default as fa_ir } from './fa_ir'