feat: adding a few more glossary definitions (#85)

src/content/docs/engineering/glossary.mdx

@@ -26,6 +26,7 @@ import glossaryRow from "./diagrams/glossary_row.png";
 
 ## B
 
+- **BLoC**: Design pattern that helps the developer to separate business logic from the UI layer with a clear separation of concerns making your app more maintainable. The library flutter_bloc facilitates to implementation of this pattern in Flutter with predefined components to manage easily events and states.
 - **BuildContext**: A handle to the location of a widget in the widget tree. It is used to obtain references to resources and widgets.
 - **Builder**: A widget that uses a callback to return a widget, useful for creating widgets based on changing state or conditions.
 
@@ -111,6 +112,7 @@ import glossaryRow from "./diagrams/glossary_row.png";
 
 ## R
 
+- **Reactive Programming**: A broader paradigm used in development where the expectation is that the data will change over time and facilitate the propagation of those changes. Flutter uses Streams and StreamBuilders to apply in real-time those changes.
 - **[Row](https://api.flutter.dev/flutter/widgets/Row-class.html)**: A widget that displays its children in a horizontal array. It's commonly used for arranging elements side by side.
 
 <Diagram
@@ -128,6 +130,7 @@ import glossaryRow from "./diagrams/glossary_row.png";
 - **State Management**: It refers to the process used to share the application state across different screens.
 - **StatelessWidget**: A widget that cannot change its state: once built, it remains immutable, and if any internal property needs to be updated the widget itself can't do it.
 - **StatefulWidget**: A widget that can change its state over time. It can rebuild itself based on changes to its internal state or external data.
+- **Stream**: Asynchronous pipeline of data that can emit events allowing you to react in real-time to those.
 - **StreamBuilder**: A widget that builds its UI based on the latest value of a stream.
 
 ## T