Drop CSS icons for SVGs (#22708)

* add the svg icon as a partial so we can include it easily

* add the icon to the homepage

* drop .bd-booticon for svgs here

* rip out the import for .bd-booticon sass file

* Delete _booticon.scss

* indentation

* Update bootstrap-icon.html

* remove those

docs/assets/scss/docs.scss

@@ -39,7 +39,6 @@ $bd-warning:        #f0ad4e;
 $bd-info:           #5bc0de;
 
 // Load docs components
-@import "booticon";
 @import "nav";
 @import "masthead";
 @import "featurettes";