Add VCEP specifications

[gromdimon]

Issue:

• Closes Add VCEP informations #181

Description:

• Added VCEP specs
• Improved docstrings

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.44%. Comparing base (12f6e41) to head (80410b8).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #184      +/-   ##
==========================================
+ Coverage   86.32%   86.44%   +0.11%     
==========================================
  Files          63       63              
  Lines        3847     3880      +33     
==========================================
+ Hits         3321     3354      +33     
  Misses        526      526              

Files with missing lines	Coverage Δ
src/vcep/brain_malformations.py	100.00% <100.00%> (ø)
src/vcep/cardiomyopathy.py	100.00% <100.00%> (ø)
src/vcep/cdh1.py	100.00% <100.00%> (ø)
src/vcep/cerebral_creatine_deficiency_syndromes.py	100.00% <100.00%> (ø)
src/vcep/coagulation_factor_deficiency.py	98.03% <100.00%> (+0.03%)	⬆️
src/vcep/congenital_myopathies.py	100.00% <100.00%> (ø)
src/vcep/dicer1.py	100.00% <100.00%> (ø)
src/vcep/enigma.py	100.00% <100.00%> (ø)
src/vcep/epilepsy_sodium_channel.py	100.00% <100.00%> (ø)
src/vcep/familial_hypercholesterolemia.py	100.00% <100.00%> (ø)
... and 23 more