Added a smoothing and strikethrough option to font loading. (#1087)

* Added a smoothing option to font loading.
* Added a font strikethrough option to font loading.
* Fixed underline applying incorrectly in cases of non-underlined fallback fonts being used.

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>

docs/api/renderer.lua

@@ -24,6 +24,8 @@ renderer.color = {}
 -- @field public bold boolean
 -- @field public italic boolean
 -- @field public underline boolean
+-- @field public smoothing boolean
+-- @field public strikethrough boolean
 renderer.fontoptions = {}
 
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