fix(api-doc-types): ParameterDoc incorrectly extends ExportDoc

[devversion]

• Fixes that the ParameterDoc class incorrectly extends the ExportDoc class. This is a wrong assumption, because parameters are never individually exported. Meaning that a simple instanceof ExportDoc check will not work properly.
• Fixes that the text output of the TypeScript package prints with different line-feed kinds. Now it always uses LF, which is also being used in the tests (fixes tests on Windows, makes docs output git-diffable within Git).
• Automatically sorts imports and removes unused imports. Imports that are needed to avoid TS errors (Return type of public method from exported class has or is using name) are now used explicitly (code health improvement)

Fixes #261

[petebacondarwin]

Oops, I meant that the interface should stay the same and we should insert a new class BaseApiDoc between the interface and the ExportDoc. This would also avoid the BC.

[devversion]

@petebacondarwin I see. Updated the PR to no longer include the breaking change. Let me know if you still want me to change that lack-of declaration comment.

[devversion]

I agree with the separation of the BaseApiDoc class, the fix for the ParameterDoc and the line feed change. It was just more convenient to change stuff as part of the big change, because otherwise it would likely end up in merge conflicts.

About the BaseApiDoc. I didn't really expect this to be announced as a feature, because it's more likely being used internally only.

[devversion]

@petebacondarwin Just tried to do what you proposed. Although I included the TypeScript style changes into the ParameterDoc commit because otherwise, it would be more work to reorganize the imports for the individual commits. Hope that's fine like that.