[docs] Generate OwnTone documentation with MkDocs

- Copy existing README*.md and INSTALL.md files to docs folder
- Set up MkDocs to build documentation (mkdocs.yml)
- Add new index.md with a quick overview of OwnTone

docs/assets/extra.css

@@ -0,0 +1,86 @@
+/*
+ * MkDocs Material theme buttons have wrong colors for the theme
+ * setting:
+ *
+ *    palette:
+ *        scheme: default
+ *        primary: white
+ *
+ * Thus the following CSS overwrites the button background- and
+ * text-colors.
+ */
+.md-button {
+  color: var(--md-accent-fg-color) !important;
+  border-color: currentColor !important;
+}
+.md-button:focus,
+.md-button:hover {
+  color: var(--md-primary-fg-color) !important;
+  background-color: var(--md-accent-fg-color) !important;
+  border-color: var(--md-accent-fg-color) !important;
+}
+
+/*
+ * The nav title has a click handler to scroll to the top
+ */
+.md-header-nav__title {
+  cursor: pointer;
+}
+
+/*
+ * Text alignment
+ */
+.text-center {
+  text-align: center;
+}
+
+/*
+ * Custom CSS for images
+ */
+.hidden {
+  visibility: hidden;
+  opacity: 0;
+  transition: visibility 0s linear 300ms, opacity 300ms;
+}
+.visible {
+  visibility: visible;
+  opacity: 1;
+  transition: visibility 0s linear 0s, opacity 300ms;
+}
+.fullscreen-image-background {
+  z-index: 25;
+  background-color: rgba(10, 10, 10, 0.5);
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  top: 0;
+}
+.fullscreen-image-background img {
+  transition: opacity 1s;
+  cursor: zoom-out;
+  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
+  z-index: 100;
+  position: fixed;
+  left: 0;
+  right: 0;
+  top: 0;
+  bottom: 0;
+  margin: 1rem auto;
+  max-height: calc(100vh - 2rem);
+  width: auto;
+}
+.zoom {
+  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
+  border-radius: 0.2rem;
+  margin: 0.5rem;
+  width: 25%;
+  cursor: zoom-in;
+}
+.zoom-wrapper {
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  justify-content: center;
+  flex-wrap: wrap;
+}

docs/assets/extra.js

@@ -0,0 +1,32 @@
+/*
+ * Add click event handler for images with class="zoom"
+ */
+document.querySelectorAll('img.zoom').forEach(item => {
+    const p = item.parentElement;
+    if (!p.classList.contains('processed')) {
+        p.classList.add('processed');
+        if (p.querySelectorAll('img.zoom').length === p.children.length) {
+            p.classList.add('zoom-wrapper');
+        }
+    }
+    item.addEventListener('click', function () {
+        const img = document.getElementById('fullscreen-image-img');
+        img.setAttribute('src', this.getAttribute('src'));
+        img.setAttribute('alt', this.getAttribute('alt'));
+
+        const div = document.getElementById('fullscreen-image');
+        div.classList.replace('hidden', 'visible');
+    })
+});
+
+var div = document.createElement('div');
+div.classList.add('fullscreen-image-background', 'hidden');
+div.id = 'fullscreen-image';
+var img = document.createElement('img');
+img.id = 'fullscreen-image-img';
+div.appendChild(img);
+
+div.addEventListener('click', function () {
+    this.classList.replace('visible', 'hidden');
+});
+document.body.appendChild(div);

docs/assets/logo.svg

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 25.2.1, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 512 512" style="enable-background:new 0 0 512 512;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#107A66;}
+	.st1{fill:#479386;}
+	.st2{fill:#00D1B2;}
+	.st3{fill:#FFFFFF;}
+</style>
+<path class="st0" d="M390.5,193.9h30.3c18.5,49.6,13.9,104.8-12.7,150.6c-5.1,8.8-11,17.2-17.6,24.9V193.9z"/>
+<path class="st1" d="M440.3,163.9h-79.8v269.6C453.8,378.5,488.6,260.8,440.3,163.9L440.3,163.9z"/>
+<path class="st2" d="M256,432c-97,0-176-79-176-176S159,80,256,80c26.9-0.1,53.4,6.1,77.5,17.9H187.9v96h99.8v235.2
+	C277.2,431,266.6,432,256,432z"/>
+<path class="st1" d="M157.9,147.8v76.1h99.8v178H256c-80.6,0-146-65.4-145.9-146.1c0-38.7,15.4-75.8,42.7-103.1
+	C154.4,151,156.1,149.4,157.9,147.8 M256,50C142.2,50,50,142.2,50,256s92.2,206,206,206c20.9,0,41.7-3.2,61.7-9.4V163.9h-99.8v-36
+	h199.4C378.3,78.6,318.8,49.9,256,50z"/>
+<path class="st2" d="M429.7,183.5c19.7,46.8,19.7,99.6,0,146.4c-12.9,30.1-33.2,56.4-59.2,76.3v3.8c48.5-36,77-92.9,77-153.3
+	c0.1-28.4-6.3-56.4-18.5-82h-3.3C427.1,177.6,428.5,180.5,429.7,183.5z"/>
+<path class="st2" d="M434,256.7c0.1-28.5-6.8-56.7-20-82h-3.4c2.4,4.6,4.7,9.3,6.7,14.1c18.3,43.4,18.3,92.4,0,135.8
+	c-8.8,20.7-21.5,39.6-37.4,55.5c-3,3-6.2,5.9-9.4,8.7v3.9C410.8,359,434,309.2,434,256.7z"/>
+<path class="st2" d="M420.5,256.7c0-28.8-7.5-57.1-21.9-82h-3.5c3.7,6.2,6.9,12.7,9.8,19.3c25.6,60.3,11.9,130.1-34.4,176.4v4.2
+	C402.5,343.7,420.5,301.2,420.5,256.7z"/>
+<path class="st2" d="M382.7,174.7h-3.5c5.2,7.8,9.6,16,13.2,24.6c21.3,50.5,12.9,108.7-21.9,151v4.7
+	C414.2,304.3,419.1,230.8,382.7,174.7z"/>
+<path class="st2" d="M370.5,180.7v5.5c26.7,43.2,26.7,97.8,0,141v5.5C401.1,286.7,401.1,226.7,370.5,180.7z"/>
+<g>
+	<path class="st3" d="M417.3,127.9H217.9v36h99.8v288.7c15.1-4.7,29.5-11.2,42.8-19.1V163.9h79.8C433.9,151.1,426.2,139,417.3,127.9
+		z"/>
+</g>
+</svg>