docs: branding fixes (#14132)

Angular 1.x -> AngularJS
Angular 1 -> AngularJS
Angular1 -> AngularJS
Angular 2+ -> Angular
Angular 2.0 -> Angular
Angular2 -> Angular

I have deliberately not touched any of the symbol names as that would cause big merge collisions with Tobias's work.

All the renames are in .md, .json, and inline comments and jsdocs.

PR Close #14132

modules/@angular/compiler-cli/README.md

@@ -105,19 +105,19 @@ This program mimics the TypeScript tsc command line. It accepts a `-p` flag whic
 This CLI is intended for demos, prototyping, or for users with simple build systems
 that run bare `tsc`.
 
-Users with a build system should expect an Angular 2 template plugin. Such a plugin would be
+Users with a build system should expect an Angular template plugin. Such a plugin would be
 based on the `index.ts` in this directory, but should share the TypeScript compiler instance
 with the one already used in the plugin for TypeScript typechecking and emit.
 
 ## Design
 At a high level, this program
-- collects static metadata about the sources using the `tsc-wrapped` package in angular2
-- uses the `OfflineCompiler` from `angular2/src/compiler/compiler` to codegen additional `.ts` files
+- collects static metadata about the sources using the `tsc-wrapped` package
+- uses the `OfflineCompiler` from `@angular/compiler` to codegen additional `.ts` files
 - these `.ts` files are written to the `genDir` path, then compiled together with the application.
 
 ## For developers
 ```
-# Build angular2 and the compiler
+# Build Angular and the compiler
 ./build.sh
 
 # Copy over the package so we can test the compiler tests

modules/@angular/compiler-cli/src/codegen.ts

@@ -22,7 +22,7 @@ import {PathMappedCompilerHost} from './path_mapped_compiler_host';
 const GENERATED_META_FILES = /\.json$/;
 
 const PREAMBLE = `/**
- * @fileoverview This file is generated by the Angular 2 template compiler.
+ * @fileoverview This file is generated by the Angular template compiler.
  * Do not edit.
  * @suppress {suspiciousCode,uselessCode,missingProperties}
  */