Feat: APA sentence

[elpiel]

@ANG13T I did my best to merge the different commits from the 2 different branches and PRs that you opened.

I also had to fix 2 issues - 1 with serde and 1 with the Cargo.toml workspace members.
Feel free to take a look and raise any issue you find, I'll merge this once all checks pass.

PRs which this PR is based on: #119 #120

[codecov]

Codecov Report

Attention: Patch coverage is 85.00000% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 77.96%. Comparing base (62763a5) to head (b337b7c).

Files	Patch %	Lines
src/sentences/apa.rs	85.96%	8 Missing ⚠️
src/parser.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #123      +/-   ##
==========================================
+ Coverage   77.62%   77.96%   +0.33%     
==========================================
  Files          34       35       +1     
  Lines        1247     1307      +60     
==========================================
+ Hits          968     1019      +51     
- Misses        279      288       +9     

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