Issue on weekly-executed GitHub workflow

[jihoon-seo]

Problem:

• weekly-contributions.yml, whose name is Update Attributions Weekly, does
  1. actions/checkout@v2
  2. actions/setup-node@v1
     but nothing else after.
• weekly.yml, whose name is Weekly issue updates, does
  not only Update all the translation issues on a nightly basis,
  but also Updates the attribution.json file in git.

Proposed Solution:

To make things clear,

• Separate two jobs into two yml files, or
• Change the name of weekly.yml to represent two jobs.

Files to Update:

• weekly-contributions.yml
• weekly.yml