allow using lower suffix for pascalCase in filename-case rule

[alexander-akait]

For example:

FooBar.test.js

Why?

1. Some tools use/recommend lower notation for part after ., for example jest use lower test (FooBar.test.js) in examples for class testing.
2. Sometimes you have vendor libraries (not in node_modules) and they use notation Timer.min.js (rare use case)
3. Code for multiple platform, for example: MyClass.web.js, MyClass.android.js (react/react-native/other same tools)

Or maybe option to configure this

[fisker]

how about a whitelist？

[alexander-akait]

Sounds good, maybe will be great allow whitelist using regexp

[alexander-akait]

WIP on the whitelist option.

Other case - i use eslint-plugin-markdown for linting code in Markdown files (using kebabCase and pascalCase values) so the filename-case rule report on some files, for example .github/ISSUE_TEMPLATE can be written in kebabCase or pascalCase.

Also many developers use README.md and CHANGELOG.md as standard practice.

[alexander-akait]

Maybe we should use ignore name because eslint uses ignore as options in some rules, anyway it will be easy to rename

[fisker]

ignore sounds better

[sindresorhus]

Let’s go with ignore.