Dashboard: Transfer authority for translation files to each i18n team.

[shu-mutou]

What would you like to be added

• Separate each translation files into its locale directory, e.g. i18n/fr/messages.fr.xlf.
• Put OWNERS file that includes each translation members into their directories, e.g. i18n/fr/OWNERS.
• Change our scripts for i18n workflow.

Why is this needed

Translation files should be reviewed by each i18n team.

Comments

none

[shu-mutou]

TODOs:

• [x] Move translation files into language directories, i.e. i18n/xx/messages.xx.xlf
• [x] Add OWNERS file into each language directories.
• [x] Modify xliffmergeOptions in package.json and check npm run check:i18n and npm run fix:i18n.
• [x] Modify aio/scripts/pre-commit-i18n.sh and check it with git commit.
• [x] Modify aio/scripts/build.sh and check npm run build and npm run start:prod.
• [x] Update docs

[shu-mutou]

@feloy @seokho-son Authority for translation files are transfered to you guys!! So please compose your translation team with i18n/[locale]/OWNERS file. :tada:

[shu-mutou]

@fuergaosi233 If you have willing to review/approve Chinese translation file, please submit PR for creation i18n/zh/OWNERS file.