Fix extend not rendered when wrapped by with

[benblakely]

These changes are now available in 1.10.4

When an #extend was wrapped by a #with, the #extend wasn't rendered.

Fixes #128

[codecov-commenter]

Codecov Report

Merging #129 (63f8ad9) into main (547a134) will increase coverage by 0.12%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #129      +/-   ##
==========================================
+ Coverage   81.95%   82.08%   +0.12%     
==========================================
  Files          25       25              
  Lines        2593     2595       +2     
==========================================
+ Hits         2125     2130       +5     
+ Misses        468      465       -3     

Files	Coverage Δ
Sources/LeafKit/LeafSyntax/LeafSyntax.swift	90.65% <100.00%> (+1.21%)	⬆️

... and 1 file with indirect coverage changes

[gwynne]

This looks fine at a glance, but I'd feel better if you could add another test or two that shows (or at least tries to show, since you can't necessarily prove a negative) that this change doesn't accidentally allow otherwise invalid syntax. (I can't claim to have dealt with the LeafKit code anywhere near recently enough to be able to suggest anything more specific than that, unfortunately 😕. @0xTim might, though.)

[0xTim]

Thanks for this, I think we're good here as it was mainly an oversight when the with tag was added