docs(forms): remove unnecessary step of installing Bootstrap (angular#3104)

Author: marcin-mazurek

public/docs/js/latest/guide/forms.jade

@@ -230,14 +230,9 @@ code-example(format="").
     ... or none at all.
 
 :marked
-  Let's add the stylesheet.
-
-ol
-  li Open a terminal window in the application root folder and enter the command:
-    code-example(language="html" escape="html").
-      npm install bootstrap --save
-  li Open <code>index.html</code> and add the following link to the <code>&lt;head></code>.
-      +makeExample('forms/js/index.html', 'bootstrap')(format=".")
+  Let's add the stylesheet. Open <code>index.html</code> and add the following link to the <code>&lt;head></code>.
++makeExample('forms/js/index.html', 'bootstrap')(format=".")
+
 :marked
 .l-main-section
 :marked

public/docs/ts/latest/guide/forms.jade

@@ -244,14 +244,9 @@ code-example(format="").
     ... or none at all.
 
 :marked
-  Let's add the stylesheet.
-
-ol
-  li Open a terminal window in the application root folder and enter the command:
-    code-example(language="html" escape="html").
-      npm install bootstrap --save
-  li Open <code>index.html</code> and add the following link to the <code>&lt;head></code>.
-      +makeExample('forms/ts/index.html', 'bootstrap')(format=".")
+  Let's add the stylesheet. Open <code>index.html</code> and add the following link to the <code>&lt;head></code>.
++makeExample('forms/ts/index.html', 'bootstrap')(format=".")
+
 :marked
 .l-main-section
 :marked