Update Docusaurus configuration and custom CSS

Author: karan925

src/css/custom.css

@@ -106,3 +106,19 @@ a[docid="docs"] > svg {
     font-size: 1.25rem;
     font-weight: 700;
 }
+
+/* Light mode Discord icon */
+/* .header-discord-link:before {
+    -webkit-filter: invert(100%);
+    filter: invert(100%);
+    content: "";
+    display: flex;
+    height: 16px;
+    width: 20px;
+} */
+
+/* Dark mode Discord icon */
+/* .header-discord-link:before {
+    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' height='16' width='20' viewBox='0 0 640 512'%3E%3Cpath fill='%23FFFFFF' d='M524.5 69.8a1.5 1.5 0 0 0 -.8-.7A485.1 485.1 0 0 0 404.1 32a1.8 1.8 0 0 0 -1.9 .9 337.5 337.5 0 0 0 -14.9 30.6 447.8 447.8 0 0 0 -134.4 0 309.5 309.5 0 0 0 -15.1-30.6 1.9 1.9 0 0 0 -1.9-.9A483.7 483.7 0 0 0 116.1 69.1a1.7 1.7 0 0 0 -.8 .7C39.1 183.7 18.2 294.7 28.4 404.4a2 2 0 0 0 .8 1.4A487.7 487.7 0 0 0 176 479.9a1.9 1.9 0 0 0 2.1-.7A348.2 348.2 0 0 0 208.1 430.4a1.9 1.9 0 0 0 -1-2.6 321.2 321.2 0 0 1 -45.9-21.9 1.9 1.9 0 0 1 -.2-3.1c3.1-2.3 6.2-4.7 9.1-7.1a1.8 1.8 0 0 1 1.9-.3c96.2 43.9 200.4 43.9 295.5 0a1.8 1.8 0 0 1 1.9 .2c2.9 2.4 6 4.9 9.1 7.2a1.9 1.9 0 0 1 -.2 3.1 301.4 301.4 0 0 1 -45.9 21.8 1.9 1.9 0 0 0 -1 2.6 391.1 391.1 0 0 0 30 48.8 1.9 1.9 0 0 0 2.1 .7A486 486 0 0 0 610.7 405.7a1.9 1.9 0 0 0 .8-1.4C623.7 277.6 590.9 167.5 524.5 69.8zM222.5 337.6c-29 0-52.8-26.6-52.8-59.2S193.1 219.1 222.5 219.1c29.7 0 53.3 26.8 52.8 59.2C275.3 311 251.9 337.6 222.5 337.6zm195.4 0c-29 0-52.8-26.6-52.8-59.2S388.4 219.1 417.9 219.1c29.7 0 53.3 26.8 52.8 59.2C470.7 311 447.5 337.6 417.9 337.6z'/%3E%3C/svg%3E")
+        no-repeat;
+} */