Correct twig documentation in various Olivero templates

From @lauriii in #216 in #3111409: Add new Olivero frontend theme to Drupal 9.1 core as beta

These are theme overrides.

+++ b/core/themes/olivero/templates/field/field--comment.html.twig
@@ -0,0 +1,57 @@
+ * Default theme override for comment fields.

+++ b/core/themes/olivero/templates/form--search-block-form.html.twig
@@ -0,0 +1,15 @@
+ * Default theme implementation for a 'form' element.

+++ b/core/themes/olivero/templates/form/field-multiple-value-form.html.twig
@@ -0,0 +1,50 @@
+ * Default theme implementation for an individual form element.

+++ b/core/themes/olivero/templates/menu-local-action.html.twig
@@ -0,0 +1,17 @@
+ * Default theme implementation for a single local action link.

+++ b/core/themes/olivero/templates/navigation/toolbar.html.twig
@@ -0,0 +1,51 @@
+ * Default theme implementation for the administrative toolbar.

+++ b/core/themes/olivero/templates/user/user--compact.html.twig
@@ -0,0 +1,25 @@
+ * Default theme implementation to present all user data.

+++ b/core/themes/olivero/templates/user/username.html.twig
@@ -0,0 +1,31 @@
+ * Default theme implementation for displaying a username.

+++ b/core/themes/olivero/templates/views/views-view--frontpage.html.twig
@@ -0,0 +1,94 @@
+ * Default theme implementation for main view template.