Add publicKeyCredential method descriptions (#25610)

Author: chrisdavidmills

Diff for: api/PublicKeyCredential.json

@@ -96,6 +96,7 @@
       },
       "getClientCapabilities_static": {
         "__compat": {
+          "description": "`getClientCapabilities()` static method",
           "spec_url": "https://w3c.github.io/webauthn/#sctn-getClientCapabilities",
           "tags": [
             "web-features:webauthn"
@@ -133,6 +134,7 @@
       },
       "getClientExtensionResults": {
         "__compat": {
+          "description": "`getClientExtensionResults()` method",
           "mdn_url": "https://developer.mozilla.org/docs/Web/API/PublicKeyCredential/getClientExtensionResults",
           "spec_url": "https://w3c.github.io/webauthn/#ref-for-dom-publickeycredential-getclientextensionresults",
           "tags": [
@@ -477,6 +479,7 @@
       },
       "signalAllAcceptedCredentials_static": {
         "__compat": {
+          "description": "`signalAllAcceptedCredentials()` static method",
           "spec_url": "https://w3c.github.io/webauthn/#dom-publickeycredential-signalallacceptedcredentials",
           "support": {
             "chrome": {
@@ -515,6 +518,7 @@
       },
       "signalCurrentUserDetails_static": {
         "__compat": {
+          "description": "`signalCurrentUserDetails()` static method",
           "spec_url": "https://w3c.github.io/webauthn/#dom-publickeycredential-signalcurrentuserdetails",
           "support": {
             "chrome": {
@@ -553,6 +557,7 @@
       },
       "signalUnknownCredential_static": {
         "__compat": {
+          "description": "`signalUnknownCredential()` static method",
           "spec_url": "https://w3c.github.io/webauthn/#dom-publickeycredential-signalunknowncredential",
           "support": {
             "chrome": {
@@ -591,6 +596,7 @@
       },
       "toJSON": {
         "__compat": {
+          "description": "`toJSON()` method",
           "mdn_url": "https://developer.mozilla.org/docs/Web/API/PublicKeyCredential/toJSON",
           "spec_url": "https://w3c.github.io/webauthn/#dom-publickeycredential-tojson",
           "tags": [