Improve new docs site. (#2843)

* Improve parameter padding and add discord link.

* Update xref service for docs.

Reason: https://github.com/dotnet/docfx/issues/9659

* Update docs readme to specify docfx version.

* Update to latest DocFX.

* update action & add manual trigger

docs/_template/material/public/main.css

@@ -183,12 +183,17 @@ code {
   box-shadow: var(--card-box-shadow);
 }
 
-/* MAKES DERIVED LIST READABLE */
-:is(dl.typelist.derived, dl.typelist.extensionMethods) > dd > div::after {
+/* MAKES PARAMETERS MORE SPACIOUS */
+dl.parameters > dt > code {
+    padding: 3px;
+}
+
+/* MAKES INHERITANCE LIST READABLE */
+:is(dl.typelist.inheritedMembers, dl.typelist.extensionMethods) > dd > div::after {
   content: none !important;
 }
 
-:is(dl.typelist.derived, dl.typelist.extensionMethods) > dd > div {
+:is(dl.typelist.inheritedMembers, dl.typelist.extensionMethods) > dd > div {
   display: block !important;
 }
 
@@ -212,7 +217,7 @@ article[data-uid="Root.Landing"] img[alt="logo"] {
 }
 
 /* MAKES SIDEBAR LINKS A BIT MORE DISTINGUISHABLE */
-.affix ul li a {
+.affix ul li a:not(.link-body-emphasis) {
   display: block !important;
   margin-left: 8px !important;
 }

docs/_template/material/public/main.js

@@ -4,6 +4,11 @@
             icon: 'github',
             href: 'https://github.com/discord-net/Discord.Net',
             title: 'GitHub'
+        },
+        {
+            icon: 'discord',
+            href: 'https://discord.gg/dnet',
+            title: 'Discord'
         }
     ]
 }