Bump node-forge from 1.3.2 to 1.4.0 in /docs (#520)

Bumps [node-forge](https://github.com/digitalbazaar/forge) from 1.3.2 to 1.4.0.
- [Changelog](https://github.com/digitalbazaar/forge/blob/main/CHANGELOG.md)
- [Commits](digitalbazaar/forge@v1.3.2...v1.4.0)

---
updated-dependencies:
- dependency-name: node-forge
  dependency-version: 1.4.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

docs/package-lock.json

@@ -13,6 +13,6 @@
   "license": "MIT",
   "devDependencies": {
     "vuepress": "^1.5.4",
-    "node-forge": ">=1.3.2"
+    "node-forge": ">=1.4.0"
   }
 }