Fix Erlang and Elixir highlight mappings (#7044)

Author: rnowak

modules/highlight/highlight.go

@@ -26,45 +26,47 @@ var (
 
 	// Extensions that are same as highlight classes.
 	highlightExts = map[string]struct{}{
-		".arm":    {},
-		".as":     {},
-		".sh":     {},
-		".cs":     {},
-		".cpp":    {},
-		".c":      {},
-		".css":    {},
-		".cmake":  {},
-		".bat":    {},
-		".dart":   {},
-		".patch":  {},
-		".elixir": {},
-		".erlang": {},
-		".go":     {},
-		".html":   {},
-		".xml":    {},
-		".hs":     {},
-		".ini":    {},
-		".json":   {},
-		".java":   {},
-		".js":     {},
-		".less":   {},
-		".lua":    {},
-		".php":    {},
-		".py":     {},
-		".rb":     {},
-		".scss":   {},
-		".sql":    {},
-		".scala":  {},
-		".swift":  {},
-		".ts":     {},
-		".vb":     {},
-		".yml":    {},
-		".yaml":   {},
+		".arm":   {},
+		".as":    {},
+		".sh":    {},
+		".cs":    {},
+		".cpp":   {},
+		".c":     {},
+		".css":   {},
+		".cmake": {},
+		".bat":   {},
+		".dart":  {},
+		".patch": {},
+		".erl":   {},
+		".go":    {},
+		".html":  {},
+		".xml":   {},
+		".hs":    {},
+		".ini":   {},
+		".json":  {},
+		".java":  {},
+		".js":    {},
+		".less":  {},
+		".lua":   {},
+		".php":   {},
+		".py":    {},
+		".rb":    {},
+		".scss":  {},
+		".sql":   {},
+		".scala": {},
+		".swift": {},
+		".ts":    {},
+		".vb":    {},
+		".yml":   {},
+		".yaml":  {},
 	}
 
 	// Extensions that are not same as highlight classes.
 	highlightMapping = map[string]string{
-		".txt": "nohighlight",
+		".txt":     "nohighlight",
+		".escript": "erlang",
+		".ex":      "elixir",
+		".exs":     "elixir",
 	}
 )