* docs: centralize translated READMEs
Keep new language additions scoped to the shared index instead of updating every localized README variant.
* docs: remove duplicated root translation files
Keep the translated README sources under readmes/ so the root only points to the shared index.
* docs: compact README language listings
Rename the translated README folder to translated_readmes and keep the English language lists on single lines with the current app i18n locales.
