minor symfony#6676 Removed 'html' from the component description (naroga)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes symfony#6676).

Discussion
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Removed 'html' from the component description

Removed a single word from the component description, to clarify that `symfony/form` is not responsible for rendering html forms (it's `symfony/twig-bundle` that does this).

This comes from a discussion, here: https://www.reddit.com/r/PHP/comments/4oj05y/symfony_rest_api_validating_data_that_will_be/d4e7fuq?context=3

Commits
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d590273 Removed 'html' from the component description

Author: wouterj

components/form/introduction.rst

@@ -5,8 +5,7 @@
 The Form Component
 ==================
 
-    The Form component allows you to easily create, process and reuse HTML
-    forms.
+    The Form component allows you to easily create, process and reuse forms.
 
 The Form component is a tool to help you solve the problem of allowing end-users
 to interact with the data and modify the data in your application. And though