Feature/custom dropdown classes (#339)

* button class property type fixed

* added support for custom classes in dropdown component

* .vscode added to .gitignore

* fix: triggerClass added to trigger element

* trigger button dynamic classes simplified

* dropdown documentation updated

* aria attributes added to dropdown trigger button

* list group content wrapper class fixed

* wording fixed in API descriptions

* Fixed typos

* Make dropdown content longer to better visualize differences between different alignment options

---------

Co-authored-by: Daniel Fahl <daniel.fahl@thomann.io>

Author: Sqrcz

.gitignore

@@ -74,6 +74,9 @@ jspm_packages/
 .vuepress/dist
 docs/.vitepress/cache
 
+# VSCode custom configs
+.vscode
+
 # Stores VSCode versions used for testing VSCode extensions
 .vscode-test