examples: fix grammer in README

Author: Cogitri

examples/virtual_methods/README.md

@@ -3,13 +3,13 @@
 Example for how to create a base widget which exposes virtual methods that other widgets can override.
 In this case, a `BaseButton` class is defined which is a gtk::Button with two additional methods:
 
-* `sync_method`: Synchonous method that updates the button label to `BaseButton sync`, or `BaseButton sync {}`
-   where {} is replaced with the `extra_text` parameter, if it's `Some`. This demos how arguments
+* `sync_method`: Synchronous method that updates the button label to `BaseButton sync`, or `BaseButton sync {}`
+   where {} is replaced with the `extra_text` parameter, if it's `Some`. This showcases how arguments
    can be added to virtual methods. The `Option<String>` has to be boxed to be FFI-safe.
-* `async_method` `Asynchronous method that updates the button label to `BaseButton async`
+* `async_method`: Asynchronous method that updates the button label to `BaseButton async`
 
 `DerivedButton` overrides the two methods. During construction `sync_method` is called in
 `BaseButton` which will set the label to `BaseButton sync` for `BaseButton` and to
-`DerivedButton sync` for `DerivedButton`. In the `VirtualMethodsWindow` `connect_clicked` is
-called on both buttons and `async_method` is called on both of them and updates their
-label accordingly when clicking the button. 
+`DerivedButton sync` for `DerivedButton`. In the `VirtualMethodsWindow`, `connect_clicked` is
+called on both buttons. Each handler for `::clicked` will invoke the respective `async_method`.
+This updates the button's label accordingly when clicking it.