Adds Snyk cache file

Generated by Snyk Visual Studio extension (https://docs.snyk.io/ide-tools/visual-studio-extension)

I think can be added in all supported languages: https://docs.snyk.io/products/snyk-open-source/language-and-package-manager-support

Node.gitignore

@@ -128,3 +128,6 @@ dist
 .yarn/build-state.yml
 .yarn/install-state.gz
 .pnp.*
+
+# Snyk cache files
+.dccache