ExtendedDefaultRules and default (Text) should be mentioned on the OverloadedStrings page
## Summary
Location of documentation issue: the GHC 9.6.1 user's guide, section 6.9.6. Overloaded string literals
Issue: The section does not mention ExtendedDefaultRules and default (Text)
## Proposed improvements or changes
The page should mention ExtendedDefaultRules and default (Text) as these are sometimes necessary to get OverloadedStrings working as expected.
## Environment
* GHC version used (if appropriate):
ExtendedDefaultRules
issue