Update theia extension setup instructions

theia-extensions/theia-cf-manifest-yaml/README.md

@@ -14,6 +14,14 @@ Install npm and node.
 Install yarn.
 
     npm install -g yarn
+    
+## Install dependencies
+
+Install dependencies and compile the code.
+
+    yarn
+
+Note: it is also running `yarn rebuild:browser` and `yarn rebuild:electron`, thus one could navigate to the proper folder and launch it
 
 ## Running the browser example
 

theia-extensions/theia-spring-boot/README.md

@@ -16,6 +16,14 @@ Install yarn.
 
     npm install -g yarn
 
+## Install dependencies
+
+Install dependencies and compile the code.
+
+    yarn
+    
+Note: it is also running `yarn rebuild:browser` and `yarn rebuild:electron`, thus one could navigate to the proper folder and launch it
+
 ## Running the browser example
 
     yarn rebuild:browser