Remove v8.x parts from examples

Author: mkszepp

docs/app/components/snippets/installation-1.scss

@@ -1,5 +1 @@
-// ember-basic-dropdown v8.x
-@import "ember-basic-dropdown";
-
-// ember-basic-dropdown v9.x+
 @use "ember-basic-dropdown";

docs/app/components/snippets/styles-2.scss

@@ -1,11 +1,3 @@
-// ember-basic-dropdown v8.x
-// Define your variables first
-$ember-basic-dropdown-overlay-background: rgba(#3b5998, 0.5);
-
-// Then import the styles, which will use your variable
-@import "ember-basic-dropdown";
-
-// ember-basic-dropdown v9.x+
 // Define your variables first
 @use "ember-basic-dropdown/scss/variables.scss" with (
   $ember-basic-dropdown-overlay-background: rgba(#3b5998, 0.5)