Fixed type error for CSSProperty #3473 (#3474)
Fixed type error for CSSProperty #3473 (#3474)

* Added new TypeScript boilerplate for WebdriverIO

* Added Accessibility test ability to TypeScript boilerplate

* Fixed type errors in Webdriverio.d.ts #3473

* Support other types of CSS attributes #3473

webdriverio/webdriverio,klamping/webdriverio,klamping/webdriverio,webdriverio/webdriverio,webdriverio/webdriverio,klamping/webdriverio