apply undercurl patch for enhanced underline stylesHEADmain

Applied st-undercurl-0.9-20240103.diff cleanly with offset adjustments.

Benefits:
- Adds support for curly/wavy underlines (undercurl)
- Custom underline colors via SGR escape codes
- Compatible with Vim/NeoVim LSP diagnostics and spell-check
- Supports standard terminal features used by most modern terminals

Use cases:
- Editor spell-check with wavy underlines
- LSP warnings/errors with colored underlines
- Enhanced visual feedback in terminal applications

1 files changed, 1 insertions, 0 deletions

diff --git a/st.info b/st.info
index 8201ad6..659878c 100644
--- a/st.info
+++ b/st.info
@@ -1,4 +1,5 @@
 st-mono| simpleterm monocolor,
+	Su,
 	acsc=+C\,D-A.B0E``aaffgghFiGjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
 	am,
 	bce,