[dartdoc_test] add some ways to ignore analysis

[takumma]

add 2 ways to ignore code sample analysis.

• Ignore with tag #no-test
  • I implemented to ignore a code sample if dart#no-test is specified as the language of code block.
• ignore file with exclude option
  • I added exclude option to cli and test function. so we can ignore files or directories.

and I add public documentation and do some work to get it published!

/// ```dart#no-test
/// func() // it will not be analyzed.
/// ```

[jonasfj]

Suggested change

	# Create test file for code samples to "test/dartdoc_test.dart"
	dart run dartdoc_test add
	# Run test command
	dart test
	# Add dartdoc_test as dev dependency
	dart pub add dev:dartdoc_test
	# Create test file for code samples to "test/dartdoc_test.dart"
	dart run dartdoc_test add
	# Run test command
	dart test

[jonasfj]

[jonasfj]

I don't think we can make dart format ignore these files.
We can either disable dart format check in mono_pkg.yaml (which is a bit sad), or we can use a different extension here 🤣

Like .dart-example instead of .dart 🙈

I'm not sure I have any good ideas :/

[takumma]

I found this and, as a temporary solution, I rewrote the example so that it would not be subject to format checks.

/// 1 positional argument expected by 'factorial', but 0 found.
/// ```dart
/// final fact = factorial();
/// print(fact); // 120
/// ```