C# Documentation and tests

[mylinhdao]

C# Documentation and tests

Closes: #295

Description

• add C# documentation
• add tests for C#
• ??= counts for complexity metric
• default switch expression arm _ => expression will not be counted for complexity

  Definition of Done

A PR is only ready for merge once all the following acceptance criteria are fulfilled:

• [x] There are automated tests for newly written code and bug fixes
• [x] Documentation (README.md, UPDATE_GRAMMARS.md) has been updated

[github-actions[bot]]

Coverage Report

Status	Category	Percentage	Covered / Total
🟢	Lines	79.77% (🎯 75%)	3787 / 4747
🟢	Statements	79.77% (🎯 75%)	3787 / 4747
🟢	Functions	93.95% (🎯 90%)	171 / 182
🟢	Branches	89.67% (🎯 85%)	443 / 494

File Coverage

File	Stmts	% Branch	% Funcs	% Lines	Uncovered Lines
Changed Files
src/parser/metrics/Complexity.ts	100%	100%	100%	100%

Generated in workflow #23