docs(samples): add example tags to generated samples (#312)

PiperOrigin-RevId: 408439482
Source-Link: googleapis/googleapis@b9f6184
Source-Link: https://github.com/googleapis/googleapis-gen/commit/eb888bc214efc7bf43bf4634b470254565a659a5
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiZWI4ODhiYzIxNGVmYzdiZjQzYmY0NjM0YjQ3MDI1NDU2NWE2NTlhNSJ9

Author: gcf-owl-bot[bot]

secret-manager/package.json

@@ -8,7 +8,7 @@
   "author": "Google LLC",
   "repository": "googleapis/nodejs-secret-manager",
   "engines": {
-    "node": ">=8"
+    "node": ">=10"
   },
   "scripts": {
     "test": "c8 mocha --recursive test/ --timeout=800000"