New doc design: Sphinx Bootstrap 4 Theme

Now we use an own, mobile-first, responsive sphinx theme based on Bootstrap 4.
It makes navigation on the very long "Python module instaloader" page a lot
easier. Also, it looks better.

This solves all the problems we had with sphinx-bootstrap-theme.

docs/_static/instaloader.css

@@ -0,0 +1,74 @@
+@import url(bootstrap-4.1.3.min.css);
+a {
+  color: #008d06; }
+  a:hover {
+    color: #f48400; }
+
+code {
+  color: #212529; }
+
+.highlight {
+  border-radius: 0.3em; }
+  .highlight pre {
+    padding: 0.7em;
+    color: #fff; }
+  .highlight .c1 {
+    color: #008d06; }
+  .highlight .kn {
+    color: #f48400; }
+  .highlight .s1, .highlight .s2, .highlight .mi {
+    color: #ff7efd; }
+
+.doc-content {
+  top: 4.0625em;
+  position: relative;
+  height: calc(100vh - 4.0625em);
+  overflow-y: auto; }
+
+.doc-sidebar {
+  position: fixed;
+  padding-top: 0.5em;
+  top: 3.5625em;
+  bottom: 0;
+  right: 0;
+  overflow-y: auto; }
+  .doc-sidebar ul {
+    padding-left: 1em; }
+    .doc-sidebar ul.current {
+      list-style-type: none;
+      padding-left: 0; }
+  .doc-sidebar li {
+    padding-top: 0.2em;
+    padding-bottom: 0.2em; }
+    .doc-sidebar li a {
+      color: #008d06; }
+      .doc-sidebar li a.current, .doc-sidebar li a.active {
+        color: #f48400;
+        font-weight: 500; }
+      .doc-sidebar li a:hover {
+        color: #f48400;
+        text-decoration: none; }
+
+.admonition {
+  border-radius: 0.3em;
+  border: 1px solid #ccc;
+  background-color: #f8f9fa; }
+  .admonition .admonition-title {
+    color: #ff7efd; }
+
+.topic {
+  border-radius: 0.3em;
+  background-color: #f8f9fa; }
+
+.nav-link {
+  padding-top: 0;
+  padding-bottom: 0; }
+
+.btn-success {
+  background-color: #008d06;
+  border-color: #008d06; }
+  .btn-success:hover {
+    background-color: #f48400;
+    border-color: #f48400; }
+
+/*# sourceMappingURL=instaloader.css.map */

docs/_static/instaloader.js

@@ -0,0 +1,22 @@
+$(function () {
+    $('[data-toggle="tooltip"]').tooltip();
+
+    $('.doc-sidebar > ul > li.current').attr("id", "localtoc");
+    $('#localtoc ul').addClass("nav flex-column");
+    $('#localtoc ul li').addClass("nav-item");
+    $('#localtoc ul li a').addClass("nav-link");
+    $('.doc-content').scrollspy({target: '#localtoc'});
+
+    const top_href = '#' + $('.section:first').attr("id");
+    $('#localtoc > a.current').attr("href", top_href);
+
+    $('#navbarToc a').on("click", function () {
+        const href = $(this).attr("href");
+        if (href === '#') {
+            window.location.href = top_href;
+        } else {
+            window.location.href = href;
+        }
+        $('#navbarToc').modal('hide');
+    });
+});

docs/_static/instaloader.scss

@@ -0,0 +1,114 @@
+@import 'bootstrap-4.1.3.min.css';
+
+$color_instaloader_main: #008d06;
+$color_instaloader_accent: #f48400;
+$color_instaloader_hyper: #ff7efd;
+$color_normal_text: #212529;
+$color_light_bg: #f8f9fa;
+
+a {
+  color: $color_instaloader_main;
+
+  &:hover {
+    color: $color_instaloader_accent;
+  }
+}
+
+code {
+  color: $color_normal_text;
+}
+
+.highlight {
+  border-radius: 0.3em;
+
+  pre {
+    padding: 0.7em;
+    color: #fff;
+  }
+
+  .c1 {
+    color: $color_instaloader_main
+  }
+
+  .kn {
+    color: $color_instaloader_accent
+  }
+
+  .s1, .s2, .mi {
+    color: $color_instaloader_hyper
+  }
+}
+
+.doc-content {
+  top: 4.0625em;
+  position: relative;
+  height: calc(100vh - 4.0625em);
+  overflow-y: auto;
+}
+
+.doc-sidebar {
+  position: fixed;
+  padding-top: 0.5em;
+  top: 3.5625em;
+  bottom: 0;
+  right: 0;
+  overflow-y: auto;
+
+  ul {
+    padding-left: 1em;
+
+    &.current {
+      list-style-type: none;
+      padding-left: 0;
+    }
+  }
+
+  li {
+    padding-top: 0.2em;
+    padding-bottom: 0.2em;
+
+    a {
+      color: $color_instaloader_main;
+
+      &.current, &.active {
+        color: $color_instaloader_accent;
+        font-weight: 500;
+      }
+
+      &:hover {
+        color: $color_instaloader_accent;
+        text-decoration: none;
+      }
+    }
+  }
+}
+
+.admonition {
+  border-radius: 0.3em;
+  border: 1px solid #ccc;
+  background-color: $color_light_bg;
+
+  .admonition-title {
+    color: $color_instaloader_hyper;
+  }
+}
+
+.topic {
+  border-radius: 0.3em;
+  background-color: $color_light_bg;
+}
+
+.nav-link {
+  padding-top: 0;
+  padding-bottom: 0;
+}
+
+.btn-success {
+  background-color: $color_instaloader_main;
+  border-color: $color_instaloader_main;
+
+  &:hover {
+    background-color: $color_instaloader_accent;
+    border-color: $color_instaloader_accent;
+  }
+}

docs/_static/style.css

@@ -1,28 +0,0 @@
-code {
-    color: #222;
-    background-color: #f5f5f5;
-}
-
-dd {
-    padding-left: 8px;
-}
-
-dl.option dd {
-    padding-left: 12px;
-}
-
-a {
-    color: #008d06;
-}
-
-a:hover {
-    color: #f48400;
-}
-
-body {
-    font-size: 16px;
-}
-
-.versionmodified {
-    font-size: 14px;
-}