feat: Add nodejs, update Angular.

angular.md

@@ -8,6 +8,7 @@
   - [Auth](#auth)
 - [Frameworks](#frameworks)
 - [Errors](#errors)
+- [Testing](#testing)
 
 <!-- /TOC -->
 
@@ -35,3 +36,10 @@
 ## Errors
 
 - [Reason: Credential is not supported if the CORS header 'Access-Control-Allow-Origin' is '*'](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSNotSupportingCredentials)
+
+## Testing
+
+- SO [Angular - unit test for a subscribe function in a component](https://stackoverflow.com/q/45839955/515948)
+- SO [Angular Unit Test - Mocked Service is not being used](https://stackoverflow.com/q/54984241/515948)
+- SO [Testing error case with observables in services](https://stackoverflow.com/q/39960146/515948)
+- SO [Angular 13 TestBed doesn't inject interceptor](https://stackoverflow.com/q/71251261/515948)

nodejs.md

@@ -0,0 +1,10 @@
+# Node JS
+<!-- TOC -->
+
+- [System information](#system-information)
+
+<!-- /TOC -->
+
+## System information
+
+- [How to get the current directory in Node.js](https://attacomsian.com/blog/nodejs-get-current-directory)