fix: anchor tag safety (via #4789)

* v3.17.6

* release(3.17.6): rebuild dist

* add failing tests

* fix Link component

* fix OnlineValidatorBadge component

* switch from <a> to <Link> in operation components

* make Markdown inputs safe

* use Link component in Info block, for target safety

* add eslint rule for unsafe `target` usage

package.json

@@ -100,7 +100,7 @@
     "eslint": "^4.1.1",
     "eslint-plugin-import": "^2.13.0",
     "eslint-plugin-mocha": "^4.11.0",
-    "eslint-plugin-react": "~7.7.0",
+    "eslint-plugin-react": "^7.10.0",
     "expect": "^1.20.2",
     "extract-text-webpack-plugin": "^3.0.2",
     "file-loader": "^1.1.11",