Ligatures for single/double line separator?

[morishxt]

What

https://github.com/0xType/0xProto/issues/114#issuecomment-2842584791

for 4+ ---- and ====

Why 4+?

https://github.com/0xType/0xProto/issues/114#issuecomment-2843779245

For now, the three equals (===) are in the programming language operators so there is already a ligature and it does not extend to the full glyph width to be a separator line. So a double-line separator is a ligature for 4+ =.