add @docusaurus/theme-common

Signed-off-by: Joshua Castle <26531652+Kas-tle@users.noreply.github.com>

package.json

@@ -17,6 +17,7 @@
     "dependencies": {
         "@docusaurus/core": "^3.1.1",
         "@docusaurus/preset-classic": "^3.1.1",
+        "@docusaurus/theme-common": "^3.1.1",
         "@fortawesome/fontawesome-svg-core": "^6.5.1",
         "@fortawesome/free-brands-svg-icons": "^6.5.1",
         "@fortawesome/free-regular-svg-icons": "^6.5.1",