Exclude `node_modules` by default from JS Code Hints.

See #8646.

This can be overridden by adding a .jscodehints file and setting
excluded-directories in there.
Comment fixes
Update README.md

Correct a word!
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Merge pull request #8722 from Denisov21/patch-14

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Merge pull request #8703 from adobe/dangoor/8646-exclude-node-modules

Exclude `node_modules` by default from JS Code Hints.