Can't bind to 'ngModel' since it isn't a known property of 'input'. ("">

もう何度も同じメッセージを目撃し、時間を無駄にしているのでメモ

src/app/app.module.ts に FormsModule を追加する

 import { BrowserModule } from '@angular/platform-browser';
 import { NgModule } from '@angular/core';
+import { FormsModule } from '@angular/forms';
 
 import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './app.component';
@@ -10,7 +11,8 @@ import { AppComponent } from './app.component';
   ],
   imports: [
     BrowserModule,
-    AppRoutingModule
+    AppRoutingModule,
+    FormsModule
   ],
   providers: [],
   bootstrap: [AppComponent]