[Security] Bump highlight.js from 9.12.0 to 9.18.5

Bumps [highlight.js](https://github.com/highlightjs/highlight.js) from 9.12.0 to 9.18.5. **This update includes a security fix.**
- [Release notes](https://github.com/highlightjs/highlight.js/releases)
- [Changelog](https://github.com/highlightjs/highlight.js/blob/9.18.5/CHANGES.md)
- [Commits](https://github.com/highlightjs/highlight.js/compare/9.12.0...9.18.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package-lock.json

@@ -7704,9 +7704,9 @@
       }
     },
     "highlight.js": {
-      "version": "9.12.0",
-      "resolved": "https://registry.npmjs.org/highlight.js/-/highlight.js-9.12.0.tgz",
-      "integrity": "sha1-5tnb5Xy+/mB1HwKvM2GVhwyQwB4=",
+      "version": "9.18.5",
+      "resolved": "https://registry.npmjs.org/highlight.js/-/highlight.js-9.18.5.tgz",
+      "integrity": "sha512-a5bFyofd/BHCX52/8i8uJkjr9DYwXIPnM/plwI6W7ezItLGqzt7X2G2nXuYSfsIJdkwwj/g9DG1LkcGJI/dDoA==",
       "dev": true
     },
     "hmac-drbg": {
@@ -17175,9 +17175,9 @@
       }
     },
     "webpack-hot-middleware": {
-      "version": "2.25.0",
-      "resolved": "https://registry.npmjs.org/webpack-hot-middleware/-/webpack-hot-middleware-2.25.0.tgz",
-      "integrity": "sha512-xs5dPOrGPCzuRXNi8F6rwhawWvQQkeli5Ro48PRuQh8pYPCPmNnltP9itiUPT4xI8oW+y0m59lyyeQk54s5VgA==",
+      "version": "2.23.1",
+      "resolved": "https://registry.npmjs.org/webpack-hot-middleware/-/webpack-hot-middleware-2.23.1.tgz",
+      "integrity": "sha512-oUdCGDHONJrARtqxPSiON4db4dRWUsRiPwD7dYkglrTc3vF7LKa2jncwN0lIVkNwtoCh/yiHVTzz3Hbcux8ikA==",
       "dev": true,
       "requires": {
         "ansi-html": "0.0.7",

package.json

@@ -127,7 +127,7 @@
     "vue-template-compiler": "^2.6.10",
     "webpack": "^3.5.2",
     "webpack-dev-server": "^3.1.11",
-    "webpack-hot-middleware": "^2.25.0",
+    "webpack-hot-middleware": "^2.18.2",
     "webpack-merge": "^4.1.0"
   }
 }