Allow parsing document with unset fields defaults

[art049]

Fixes #13

• Comprehensive exception with key names
• Documentation

[github-actions]

🚀 Deployed on https://docs-preview-28--odmantic.netlify.app

[codecov-io]

Codecov Report

Merging #28 (33d4de1) into master (f72ae95) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master       #28   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           12        12           
  Lines          827       882   +55     
  Branches       135       143    +8     
=========================================
+ Hits           827       882   +55     

Flag	Coverage Δ
tests-3.6-4	99.08% <100.00%> (+0.06%)	⬆️
tests-3.6-4.2	99.08% <100.00%> (+0.06%)	⬆️
tests-3.6-4.4	99.08% <100.00%> (+0.06%)	⬆️
tests-3.7-4	98.51% <100.00%> (+0.09%)	⬆️
tests-3.7-4.2	98.51% <100.00%> (+0.09%)	⬆️
tests-3.7-4.4	98.51% <100.00%> (+0.09%)	⬆️
tests-3.8-4	98.29% <100.00%> (+0.11%)	⬆️
tests-3.8-4.2	98.29% <100.00%> (+0.11%)	⬆️
tests-3.8-4.4	98.29% <100.00%> (+0.11%)	⬆️
tests-3.9-4	98.18% <100.00%> (+0.12%)	⬆️
tests-3.9-4.2	98.18% <100.00%> (+0.12%)	⬆️
tests-3.9-4.4	98.18% <100.00%> (+0.12%)	⬆️

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

Impacted Files	Coverage Δ
odmantic/config.py	100.00% <100.00%> (ø)
odmantic/engine.py	100.00% <100.00%> (ø)
odmantic/exceptions.py	100.00% <100.00%> (ø)
odmantic/field.py	100.00% <100.00%> (ø)
odmantic/model.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f72ae95...33d4de1. Read the comment docs.