docs(rustdoc): document that JS/TS checks run under tidy (eslint, es-check, tsc) and add note about (refs #2364)

Author: ali90h

src/rustdoc-internals/rustdoc-gui-test-suite.md

@@ -7,7 +7,6 @@ For other rustdoc-specific test suites, see [Rustdoc test suites].
 
 These use a NodeJS-based tool called [`browser-UI-test`] that uses [puppeteer] to run tests in a headless browser and check rendering and interactivity. For information on how to write this form of test, see [`tests/rustdoc-gui/README.md`][rustdoc-gui-readme] as well as [the description of the `.goml` format][goml-script]
 
-
 [Rustdoc test suites]: ../tests/compiletest.md#rustdoc-test-suites
 [`browser-UI-test`]: https://github.com/GuillaumeGomez/browser-UI-test/
 [puppeteer]: https://pptr.dev/