Fixes to the Unblocking Clipboard Access article (#8184)
Fixes to the Unblocking Clipboard Access article (#8184)

In the *Unblocking Clipboard Access* article,

- Added a missing comma.
- Replaced a plain "setTimeout" with "`setTimeout()`". 
- Added missing semicolons in some code snippets.
- Added backticks around `window.clipboardData`.
google/WebFundamentals,google/WebFundamentals,myakura/WebFundamentals,myakura/WebFundamentals,myakura/WebFundamentals,google/WebFundamentals,google/WebFundamentals,myakura/WebFundamentals