Enable feedback widget (#1146)

docs/browsers.en.md

@@ -1,6 +1,9 @@
 ---
 title: "Web Browsers"
 icon: octicons/browser-16
+tags:
+  - HTML5
+  - JavaScript
 ---
 These are our current web browser recommendations and settings. We recommend keeping extensions to a minimum: they have privileged access within your browser, require you to trust the developer, can make you [stand out](https://en.wikipedia.org/wiki/Device_fingerprint#Browser_fingerprint), and [weaken](https://groups.google.com/a/chromium.org/g/chromium-extensions/c/0ei-UCHNm34/m/lDaXwQhzBAAJ) site isolation.
 

docs/index.en.md

@@ -3,6 +3,7 @@ template: overrides/home.en.html
 hide:
   - navigation
   - toc
+  - feedback
 ---
 <!-- markdownlint-disable-next-line -->
 <div style="max-width:50rem;margin:auto;" markdown>

docs/javascripts/feedback.js

@@ -0,0 +1,13 @@
+var feedback = document.forms.feedback
+feedback.removeAttribute("hidden");
+feedback.addEventListener("submit", function(ev) {
+  ev.preventDefault()
+
+  /* Retrieve page and feedback value */
+  var page = document.location.pathname
+  var data = ev.submitter.getAttribute("data-md-value")
+
+  /* Send feedback value */
+  console.log(page, data)
+  plausible(data)
+})