Refactor string formatting

[rszamszur]

Checklist:

• Added tests for changed code where applicable.
• Documentation reflects the changes where applicable.
• Updated the CHANGELOG.md file with your changes.
• My PR is ready to review.

Resolves: #133

Description of the changes being introduced by the pull request:

[github-actions]

🚀 Deployed on https://62f5310d77f4980d51443fc7--fastapi-mvc.netlify.app

[codecov-commenter]

Codecov Report

Merging #134 (e88024b) into master (18fbb9e) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #134   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           40        40           
  Lines          800       801    +1     
=========================================
+ Hits           800       801    +1     

Impacted Files	Coverage Δ
fastapi_mvc/cli/run.py	100.00% <ø> (ø)
...}/{{cookiecutter.package_name}}/app/views/error.py	100.00% <ø> (ø)
fastapi_mvc/borg.py	100.00% <100.00%> (ø)
fastapi_mvc/cli/click_custom.py	100.00% <100.00%> (ø)
fastapi_mvc/commands/run_generator.py	100.00% <100.00%> (ø)
fastapi_mvc/commands/run_shell.py	100.00% <100.00%> (ø)
fastapi_mvc/generators/controller/controller.py	100.00% <100.00%> (ø)
fastapi_mvc/generators/generator/generator.py	100.00% <100.00%> (ø)
fastapi_mvc/generators/project/project.py	100.00% <100.00%> (ø)
...cookiecutter.package_name}}/app/exceptions/http.py	100.00% <100.00%> (ø)
... and 6 more

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