feat: provide a schema file for dartgun.toml

dartgun.schema.json

@@ -0,0 +1,34 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "object",
+  "properties": {
+    "dots": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "location": {
+            "type": "string"
+          },
+          "destination": {
+            "type": "string"
+          },
+          "strategy": {
+            "type": "string",
+            "enum": ["symlink"]
+          },
+          "identifiers": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          }
+        },
+        "required": ["location", "destination", "identifiers"],
+        "additionalProperties": false
+      }
+    }
+  },
+  "required": ["dots"],
+  "additionalProperties": false
+}