Add select-search userscript and bookmarklet

Makes any <select> with many options searchable, for web apps whose
dropdowns have no search. The original <select> stays in the DOM and
remains the source of truth: choosing an option sets selectedIndex and
fires native input/change events, so the host application and its form
submission are unaffected.

Handles option lists that the app repopulates at runtime via a per-select
MutationObserver, and new selects appearing after AJAX via a document-level
one. Filtering is substring-based, accent-insensitive and multi-token.

Built into both a Tampermonkey userscript and a bookmarklet from one source.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/userscript-header.txt

@@ -0,0 +1,16 @@
+// ==UserScript==
+// @name         Doorzoekbare dropdowns (select-search)
+// @namespace    https://github.com/glgoose/select-search
+// @version      1.0.0
+// @description  Geeft elke <select> met veel opties een zoekveld met substring-zoeken.
+// @author       glgoose
+// @license      MIT
+// @homepageURL  https://github.com/glgoose/select-search
+// @supportURL   https://github.com/glgoose/select-search/issues
+// @downloadURL  https://raw.githubusercontent.com/glgoose/select-search/main/dist/select-search.user.js
+// @updateURL    https://raw.githubusercontent.com/glgoose/select-search/main/dist/select-search.user.js
+// @match        https://bipp.biotechpartner.be/web/*
+// @run-at       document-idle
+// @grant        none
+// @noframes     false
+// ==/UserScript==