fix: repair pipe test and document Bash NVM setup

src/app/fullname-pipe.spec.ts

@@ -1,8 +1,9 @@
+import { TestBed } from '@angular/core/testing';
 import { FullnamePipe } from './fullname-pipe';
 
 describe('FullnamePipePipe', () => {
   it('create an instance', () => {
-    const pipe = new FullnamePipe();
+    const pipe = TestBed.runInInjectionContext(() => new FullnamePipe());
     expect(pipe).toBeTruthy();
   });
 });