docs(custom-esbuild): align the HTML transformer signature

packages/custom-esbuild/README.md

@@ -187,19 +187,10 @@ The `@angular-builders/custom-esbuild:dev-server` is an enhanced version of the
 Since Angular 8, `index.html` is not generated as part of the build. If you want to modify your `index.html`, you should use the `indexHtmlTransformer` option. `indexHtmlTransformer` is a path (relative to the workspace root) to a `.js` or `.ts` file that exports a transformation function for `index.html`. If `indexHtmlTransformer` is written in TypeScript, the application's `tsConfig` file will be used by `tsnode` for its execution:
 
 ```typescript
-(options: TargetOptions, indexHtmlContent: string) => string | Promise<string>;
+(indexHtmlContent: string) => string | Promise<string>;
 ```
 
-or, in other words, the function receives target options and original `index.html` content (generated by Angular CLI) and returns a new content as `string` or `Promise<string>`.  
-`TargetOptions` follows `target` definition from [this](https://github.com/angular/angular-cli/blob/master/packages/angular_devkit/architect/src/input-schema.json) schema and looks like this:
-
-```typescript
-export interface Target {
-  configuration?: string;
-  project: string;
-  target: string;
-}
-```
+or, in other words, the function receives target options and original `index.html` content (generated by Angular CLI) and returns a new content as `string` or `Promise<string>`.
 
 It is useful when you want to transform your `index.html` according to the build options.
 
@@ -221,28 +212,25 @@ It is useful when you want to transform your `index.html` according to the build
 `index-html-transformer.js`:
 
 ```js
-module.exports = (targetOptions, indexHtml) => {
+module.exports = indexHtml => {
+  const gitSha = process.env.GIT_SHA;
   const i = indexHtml.indexOf('</body>');
-  const config = `<p>Configuration: ${targetOptions.configuration}</p>`;
+  const lastCommitSha = `<p>Last commit SHA: ${gitSha}</p>`;
   return `${indexHtml.slice(0, i)}
-            ${config}
+            ${lastCommitSha}
             ${indexHtml.slice(i)}`;
 };
 ```
 
 Alternatively, using TypeScript:
 
 ```ts
-import { Target } from '@angular-devkit/architect/src/input-schema';
-import { json } from '@angular-devkit/core';
-
-type TargetOptions = json.JsonObject & Target;
-
-export default (targetOptions: TargetOptions, indexHtml: string) => {
+export default (indexHtml: string) => {
+  const gitSha = process.env['GIT_SHA'];
   const i = indexHtml.indexOf('</body>');
-  const config = `<p>Configuration: ${targetOptions.configuration}</p>`;
+  const lastCommitSha = `<p>Last commit SHA1: ${gitSha}</p>`;
   return `${indexHtml.slice(0, i)}
-            ${config}
+            ${lastCommitSha}
             ${indexHtml.slice(i)}`;
 };
 ```