Fixed broken links

Author: Oxford

SUMMARY.md

@@ -22,7 +22,7 @@
 * [Observer](/observer/README.md)
   + [Installation](/observer/v1/installation.md)
   + [Examples](/observer/v1/examples.md)
-  + [API](/observer/v1/api)
+  + [API](/observer/v1/api/README.md)
 * [Observables](/observables/README.md)
 * [PlayUI](/play-ui/README.md)
   * [Installation](/play-ui/v002/installation.md)

observer/README.md

@@ -10,7 +10,7 @@ Observer is a simple set of functions for intercepting and observing JavaScript
 
 + [Installation](/observer/v1/installation.md)
 + [Examples](/observer/v1/examples.md)
-+ [API](/observer/v1/api)
++ [API](/observer/v1/api/README.md)
 
 ## Issues
 

observer/v1/installation.md

@@ -33,4 +33,4 @@ import Observer from './node_modules/@web-native-js/observer/v1/src/index.js';
 ## Usage
 
 + [Examples](/observer/v1/examples.md)
-+ [API Docs](/observer/v1/api)
++ [API Docs](/observer/v1/api/README.md)