Bump ajv from 6.12.2 to 6.12.6

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.12.2 to 6.12.6.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v6.12.2...v6.12.6)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
...

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

package-lock.json

@@ -2479,9 +2479,9 @@
       }
     },
     "ajv": {
-      "version": "6.12.3",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.3.tgz",
-      "integrity": "sha512-4K0cK3L1hsqk9xIb2z9vs/XU+PGJZ9PNpJRDS9YLzmNdX6jmVPfamLvTJr0aDAusnHyCHO6MjzlkAsgtqp9teA==",
+      "version": "6.12.6",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
       "requires": {
         "fast-deep-equal": "^3.1.1",
         "fast-json-stable-stringify": "^2.0.0",

resources/php.json

@@ -67,6 +67,12 @@
       "desc": "134 Slides to help fix your code. Performance and testing are just one aspect of code, to really be successful your code needs to be readable, maintainable and generally easier to comprehend and work with.",
       "url": "https://www.slideshare.net/rdohms/your-code-sucks-lets-fix-it-15471808",
       "tags": ["slides", "readability", "rules"]
+    },
+    {
+      "title": "Clean Code PHP",
+      "desc": "Software engineering principles, from Robert C. Martin's book Clean Code, adapted for PHP.",
+      "url": "https://github.com/jupeter/clean-code-php",
+      "tags": ["book", "guide", "rules", "standards"]
     }
   ]
-}
+}