Review API documentation

[scouten-adobe]

Checklist

• This PR represents a single feature, fix, or change.
• All applicable changes have been documented.
• Any TO DO items (or similar) have been entered as GitHub issues and the link to that issue has been included in a comment.

[codecov]

Codecov Report

Merging #153 (d52dbd9) into main (f4f0cc5) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #153   +/-   ##
=======================================
  Coverage   97.87%   97.87%           
=======================================
  Files           8        8           
  Lines        1504     1504           
=======================================
  Hits         1472     1472           
  Misses         32       32           

Impacted Files	Coverage Δ
src/xmp_date_time.rs	98.33% <ø> (ø)
src/xmp_error.rs	100.00% <ø> (ø)
src/xmp_file.rs	68.53% <ø> (ø)
src/xmp_iterator.rs	100.00% <ø> (ø)
src/xmp_meta.rs	99.80% <ø> (ø)
src/xmp_value.rs	100.00% <ø> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more