docs: explain "worldId" in the web frame docs (#14309)

Fixes #14288

docs/api/web-frame.md

@@ -133,31 +133,31 @@ this limitation.
 
 ### `webFrame.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture, callback])`
 
-* `worldId` Integer
+* `worldId` Integer - The ID of the world to run the javascript in, `0` is the default world, `999` is the world used by Electrons `contextIsolation` feature.  You can provide any integer here.
 * `scripts` [WebSource[]](structures/web-source.md)
 * `userGesture` Boolean (optional) - Default is `false`.
 * `callback` Function (optional) - Called after script has been executed.
   * `result` Any
 
-Work like `executeJavaScript` but evaluates `scripts` in isolated context.
+Work like `executeJavaScript` but evaluates `scripts` in an isolated context.
 
 ### `webFrame.setIsolatedWorldContentSecurityPolicy(worldId, csp)`
 
-* `worldId` Integer
+* `worldId` Integer - The ID of the world to run the javascript in, `0` is the default world, `999` is the world used by Electrons `contextIsolation` feature.  You can provide any integer here.
 * `csp` String
 
 Set the content security policy of the isolated world.
 
 ### `webFrame.setIsolatedWorldHumanReadableName(worldId, name)`
 
-* `worldId` Integer
+* `worldId` Integer - The ID of the world to run the javascript in, `0` is the default world, `999` is the world used by Electrons `contextIsolation` feature.  You can provide any integer here.
 * `name` String
 
 Set the name of the isolated world. Useful in devtools.
 
 ### `webFrame.setIsolatedWorldSecurityOrigin(worldId, securityOrigin)`
 
-* `worldId` Integer
+* `worldId` Integer - The ID of the world to run the javascript in, `0` is the default world, `999` is the world used by Electrons `contextIsolation` feature.  You can provide any integer here.
 * `securityOrigin` String
 
 Set the security origin of the isolated world.