Ship v4.1.0 (#26218)

* update docs path from docs/4.0/ to docs/4.1/

* bump version to 4.1.0

* Update redirects to work for 4.1 docs move

* Update docs version switcher to include latest and link to 4.0 docs

* re-run dist

* Update package-lock.json

* Update docs-navbar.html

docs/4.1/extend/icons.md

@@ -0,0 +1,29 @@
+---
+layout: docs
+title: Icons
+description: Guidance and suggestions for using external icon libraries with Bootstrap.
+group: extend
+---
+
+Bootstrap doesn't include an icon library by default, but we have a handful of recommendations for you to choose from. While most icon sets include multiple file formats, we prefer SVG implementations for their improved accessibility and vector support.
+
+## Preferred
+
+We've tested and used these icon sets ourselves.
+
+- [Font Awesome](https://fontawesome.com/)
+- [Iconic](https://useiconic.com/open/)
+- [Octicons](https://octicons.github.com/)
+
+## More options
+
+While we haven't tried these out, they do look promising and provide multiple formats—including SVG.
+
+- [Bytesize](https://github.com/danklammer/bytesize-icons)
+- [Google Material icons](https://material.io/icons/)
+- [Ionicons](http://ionicons.com/)
+- [Feather](https://feathericons.com/)
+- [Dripicons](http://demo.amitjakhu.com/dripicons/)
+- [Ikons](http://ikons.piotrkwiatkowski.co.uk/)
+- [Glyph](https://glyph.smarticons.co/)
+- [Icons8](https://icons8.com/)