Added enum example in variables section. (#25)

* Added enum example in variables section.

* Rethought the enum motivation and example.

* Fixed typo.

Author: lucavictor220

README.md

@@ -243,6 +243,59 @@ function loadPages(count: number = 10) {
 
 **[⬆ back to top](#table-of-contents)**
 
+### Use enum to document the intent
+
+Enums can help you document the intent of the code. For example when we are concerned about values being
+different rather than the exact value of those.
+
+**Bad:**
+
+```ts
+const GENRE = {
+  ROMANTIC: 'romantic',
+  DRAMA: 'drama',
+  COMEDY: 'comedy',
+  DOCUMENTARY: 'documentary',
+}
+
+projector.configureFilm(GENRE.COMEDY);
+
+class Projector {
+  // delactation of Projector
+  configureFilm(genre) {
+    switch (genre) {
+      case GENRE.ROMANTIC:
+        // some logic to be executed 
+    }
+  }
+}
+```
+
+**Good:**
+
+```ts
+enum GENRE {
+  ROMANTIC,
+  DRAMA,
+  COMEDY,
+  DOCUMENTARY,
+}
+
+projector.configureFilm(GENRE.COMEDY);
+
+class Projector {
+  // delactation of Projector
+  configureFilm(genre) {
+    switch (genre) {
+      case GENRE.ROMANTIC:
+        // some logic to be executed 
+    }
+  }
+}
+```
+
+**[⬆ back to top](#table-of-contents)**
+
 ## Functions
 
 ### Function arguments (2 or fewer ideally)