C#: Fixed adjacent string interpolations (#2402)

Author: RunDevelopment

components/prism-csharp.js

@@ -316,7 +316,7 @@
 	function createInterpolationInside(interpolation, interpolationRound) {
 		return {
 			'interpolation': {
-				pattern: re(/([^{](?:\{\{)*)<<0>>/.source, [interpolation]),
+				pattern: re(/((?:^|[^{])(?:\{\{)*)<<0>>/.source, [interpolation]),
 				lookbehind: true,
 				inside: {
 					'format-string': {

components/prism-csharp.min.js

@@ -1,5 +1,6 @@
 $"Hello, {{ {name} }}! Today is {date.DayOfWeek}, it's {date:HH:mm} now."
 $"{a,5} and {b + "" /* foo ":} */:format} {h(a, b)}"
+$"{1}{2}{3}"
 
 @$"
 "
@@ -87,6 +88,31 @@ $@"{
 		]],
 		["string", "\""]
 	]],
+	["interpolation-string", [
+		["string", "$\""],
+		["interpolation", [
+			["punctuation", "{"],
+			["expression", [
+				["number", "1"]
+			]],
+			["punctuation", "}"]
+		]],
+		["interpolation", [
+			["punctuation", "{"],
+			["expression", [
+				["number", "2"]
+			]],
+			["punctuation", "}"]
+		]],
+		["interpolation", [
+			["punctuation", "{"],
+			["expression", [
+				["number", "3"]
+			]],
+			["punctuation", "}"]
+		]],
+		["string", "\""]
+	]],
 	["interpolation-string", [
 		["string", "@$\"\n\""]
 	]],