Add Permissions Policy (aka Feature Policy) spec URLs (mdn#9586)

Author: sideshowbarker

http/headers/feature-policy.json

@@ -4,6 +4,7 @@
       "Feature-Policy": {
         "__compat": {
           "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy",
+          "spec_url": "https://w3c.github.io/webappsec-permissions-policy/#permissions-policy-http-header-field",
           "support": {
             "chrome": {
               "version_added": "60"
@@ -69,6 +70,7 @@
         "accelerometer": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/accelerometer",
+            "spec_url": "https://w3c.github.io/accelerometer/#accelerometer-interface",
             "support": {
               "chrome": {
                 "version_added": "69",
@@ -297,6 +299,7 @@
         "battery": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/battery",
+            "spec_url": "https://w3c.github.io/battery/#permissions-policy-integration",
             "support": {
               "chrome": {
                 "version_added": false,
@@ -410,6 +413,10 @@
         "display-capture": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/display-capture",
+            "spec_url": [
+              "https://w3c.github.io/mediacapture-screen-share/#permissions-policy-integration",
+              "https://w3c.github.io/permissions/#dom-permissionname-display-capture"
+            ],
             "support": {
               "chrome": {
                 "version_added": false
@@ -472,6 +479,7 @@
         "document-domain": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/document-domain",
+            "spec_url": "https://html.spec.whatwg.org/multipage/#document-domain-feature",
             "support": {
               "chrome": {
                 "version_added": "77"
@@ -534,6 +542,7 @@
         "encrypted-media": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/encrypted-media",
+            "spec_url": "https://w3c.github.io/encrypted-media/#permissions-policy-integration",
             "support": {
               "chrome": {
                 "version_added": "60"
@@ -596,6 +605,7 @@
         "fullscreen": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/fullscreen",
+            "spec_url": "https://fullscreen.spec.whatwg.org/#permissions-policy-integration",
             "support": {
               "chrome": {
                 "version_added": "62"
@@ -1335,6 +1345,7 @@
         "publickey-credentials-get": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/publickey-credentials-get",
+            "spec_url": "https://w3c.github.io/webauthn/#sctn-permissions-policy",
             "support": {
               "chrome": {
                 "version_added": "84"
@@ -1383,6 +1394,7 @@
         "sync-xhr": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/sync-xhr",
+            "spec_url": "https://xhr.spec.whatwg.org/#permissions-policy-integration",
             "support": {
               "chrome": {
                 "version_added": "65"
@@ -1597,6 +1609,7 @@
         "usb": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/usb",
+            "spec_url": "https://wicg.github.io/webusb/#permissions-policy",
             "support": {
               "chrome": {
                 "version_added": "60"
@@ -1801,6 +1814,7 @@
         "web-share": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/web-share",
+            "spec_url": "https://w3c.github.io/web-share/#permissions-policy",
             "support": {
               "chrome": {
                 "version_added": false
@@ -1865,6 +1879,7 @@
         "xr-spatial-tracking": {
           "__compat": {
             "mdn_url": "https://developer.mozilla.org/docs/Web/HTTP/Headers/Feature-Policy/xr-spatial-tracking",
+            "spec_url": "https://immersive-web.github.io/webxr/#permissions-policy",
             "support": {
               "chrome": {
                 "version_added": "79"