Chore: Add link to product docs on sidebar (#5119)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/javascript/shared/store/globalConfig.js

@@ -41,6 +41,7 @@ const state = {
 export const getters = {
   get: $state => $state,
   isOnChatwootCloud: $state => $state.deploymentEnv === 'cloud',
+  isACustomBrandedInstance: $state => $state.installationName !== 'Chatwoot',
 };
 
 export const actions = {};