Add peerDependencies and peerDependenciesMeta for canvas (#309)

Co-authored-by: Andrea Giammarchi <andrea.giammarchi@gmail.com>

Author: k35o

package-lock.json

@@ -76,6 +76,14 @@
     "htmlparser2": "^10.0.0",
     "uhyphen": "^0.2.0"
   },
+  "peerDependencies": {
+    "canvas": ">= 2"
+  },
+  "peerDependenciesMeta": {
+    "canvas": {
+      "optional": true
+    }
+  },
   "engines": {
     "node": ">=16"
   },