Servers: Add categories to server model.

src/database/entities/server.rs

@@ -46,6 +46,13 @@ pub struct Role {
     // Bri'ish API conventions
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct Category {
+    pub id: String,
+    pub title: String,
+    pub channels: Vec<String>
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct Ban {
     #[serde(rename = "_id")]
@@ -81,6 +88,8 @@ pub struct Server {
     
     pub channels: Vec<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    pub categories: Option<Vec<Category>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub system_messages: Option<SystemMessageChannels>,
 
     #[serde(default = "HashMap::new", skip_serializing_if = "HashMap::is_empty")]