Fix errors in metric_score.pkg_metric_size_codebase doc

[fh-kpikhart]

Closes #329 and #330

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 61.85%. Comparing base (7c7bf3c) to head (aa51c71).

:exclamation: Current head aa51c71 differs from pull request most recent head 6363c60. Consider uploading reports for the commit 6363c60 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #336 +/- ## ======================================= Coverage 61.85% 61.85% ======================================= Files 66 66 Lines 1025 1025 ======================================= Hits 634 634 Misses 391 391 ```

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