Better paired operators for R (microsoft#155882)

Co-authored-by: Martin Aeschlimann <[email protected]>

Author: MichaelChirico

Diff for: extensions/r/language-configuration.json

@@ -11,13 +11,16 @@
 		["{", "}"],
 		["[", "]"],
 		["(", ")"],
+		["`", "`"],
 		{ "open": "\"", "close": "\"", "notIn": ["string"] },
-		{ "open": "'", "close": "'", "notIn": ["string"] }
+		{ "open": "'", "close": "'", "notIn": ["string", "comment"] },
+		{ "open": "%", "close": "%", "notIn": ["string", "comment"] }
 	],
 	"surroundingPairs": [
 		["{", "}"],
 		["[", "]"],
 		["(", ")"],
+		["`", "`"],
 		["\"", "\""],
 		["'", "'"]
 	]