feat: add problem matcher file for dotnet-format

.github/dotnet-format.json

@@ -0,0 +1,19 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "dotnet-format",
+            "pattern": [
+                {
+                    "regexp": "^\\s*(.*)\\((\\d+),(\\d+)\\):\\s+(error|warning|info)\\s+:\\s+(.*)\\s+\\[(.+)\\]$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3,
+                    "severity": 4,
+                    "code": 5,
+                    "message": 6,
+                    "fromPath": 7
+                }
+            ]
+        }
+    ]
+}