docs: adjust docs layouts and add tables of contents

- add an auto-generated table of contents with markdown-toc
- docs pages now fill the whole page width; other pages are are 4/5ths wide as before
- clean up and reorganize some styles
- version dropdown moved to the left
- cleaned up the github edit link
- a couple of responsive cleanups
- add page title to HTML title attribute

Signed-off-by: Timothy Gerla <tim@gerla.net>

docs/website/components/GitHubLink.vue

@@ -0,0 +1,41 @@
+<template>
+  <div class="text-gray-800">
+    <a :href="link"
+      ><svg
+        xmlns="http://www.w3.org/2000/svg"
+        width="28"
+        height="28"
+        viewBox="0 0 24 24"
+        fill="none"
+        stroke="currentColor"
+        stroke-width="2"
+        stroke-linecap="round"
+        stroke-linejoin="round"
+        class="feather feather-edit text-gray-800"
+      >
+        <title>Edit on GitHub</title>
+        <path
+          d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"
+        ></path>
+        <path
+          d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"
+        ></path>
+      </svg>
+    </a>
+  </div>
+</template>
+
+<script>
+export default {
+  name: 'GitHubLink',
+
+  computed: {
+    link() {
+      const path =
+        'https://github.com/talos-systems/talos/edit/master/docs/website/content/'
+
+      return path + this.$route.params.pathMatch + '.md'
+    }
+  }
+}
+</script>