Split ENTRYPOINT to CMD in Dockerfile

[PragmaTwice]

So that users can give another config file in a relatively easy way.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 47.00%. Comparing base (6c56470) to head (b31857e).
⚠️ Report is 100 commits behind head on unstable.

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable     #359      +/-   ##
============================================
+ Coverage     43.38%   47.00%   +3.61%     
============================================
  Files            37       45       +8     
  Lines          2971     4451    +1480     
============================================
+ Hits           1289     2092     +803     
- Misses         1544     2149     +605     
- Partials        138      210      +72     

Flag	Coverage Δ
unittests	47.00% <ø> (+3.61%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.