Warn when glyphs cannot fit the atlas

Cargo.toml

@@ -35,6 +35,7 @@ image = "0.25.6"
 parley = "0.11.1"
 swash = "0.2.10"
 fxhash = "0.2.1"
+log = "0.4.29"
 arboard = "3.6.1"
 iris-core = { path = "core" }
 iris-macro = { path = "macro" }