[Suggestion] add ~= ligature for Lua

[Rosy-iso]

In the programming language Lua for some reason "~=" is used instead of "!=" and it would be really nice if a ligature for it was added

[kika]

As always, PRs are more than welcome

[Rosy-iso]

I guess I'll try making one then

[iiiGerardoiii]

I've been checking out other coding fonts to see how they treat the ~ = ligature for Lua and there's lots of discussion about whether or not should be seen as ≃, because ≃ means "asymptotically equal" and not "not equal":

• Cascadia Code uses a ligature that looks like if didn't have a ligature applied, except they're slightly closer to one another:
  

• Some other popular fonts even removed their previously implemented ligature from it (Fira Code and Jetbrains Mono, to name a few)

With those decisions in consideration, I thought of these ideas:

Personally, I think Option 3 is the best one, since their ligature version (option 2) is pretty much the same except = is 1px longer. We'd only need to move the ~ character a few pixels down.