doc: claim NODE_MODULE_VERSION=80 for Electron 9

PR-URL: #30052
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/abi_version_registry.json

@@ -1,5 +1,6 @@
 {
   "NODE_MODULE_VERSION": [
+    { "modules": 80, "runtime": "electron", "variant": "electron",             "versions": "9" },
     { "modules": 79, "runtime": "node",     "variant": "v8_7.8",               "versions": "13" },
     { "modules": 78, "runtime": "node",     "variant": "v8_7.7",               "versions": "13.0.0-pre" },
     { "modules": 77, "runtime": "node",     "variant": "v8_7.6",               "versions": "13.0.0-pre" },