chore: Add configurable per-document connection limit extension (#4717)

* chore: Add configurable per-document connection limit extension

* docs

server/env.ts

@@ -147,6 +147,17 @@ export class Environment {
     process.env.COLLABORATION_URL
   );
 
+  /**
+   * The maximum number of network clients that can be connected to a single
+   * document at once. Defaults to 100.
+   */
+  @IsOptional()
+  @IsNumber()
+  public COLLABORATION_MAX_CLIENTS_PER_DOCUMENT = parseInt(
+    process.env.COLLABORATION_MAX_CLIENTS_PER_DOCUMENT || "100",
+    10
+  );
+
   /**
    * The port that the server will listen on, defaults to 3000.
    */