scaffold: start v3 rewrite from scratch

Remove all Qt5/C++/QML source files to begin a full rewrite in
Rust + GTK4 + libadwaita. The BACKLOG.md describes the plan.

html/content.css

@@ -1,112 +0,0 @@
-/*
- * This file is part of FeedTheMonkey.
- *
- * Copyright 2015 Jeena
- *
- * FeedTheMonkey is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * FeedTheMonkey is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with FeedTheMonkey.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-html, body {
-    margin: 0;
-    padding: 0;
-}
-
-body {
-    background: #eee;
-    font-family: sans-serif;
-    word-wrap: break-word;
-}
-
-.nightmode {
-    background: #353535;
-    color: #ddd;
-}
-
-.nightmode::-webkit-scrollbar {
-    width: 8px;
-    height: 8px;
-}
-
-.nightmode::-webkit-scrollbar-track-piece  {
-    background-color: #111;
-}
-
-.nightmode::-webkit-scrollbar-thumb:vertical {
-    height: 30px;
-    background-color: #444;
-    border-radius: 5px;
-}
-
-h1 {
-    font-size: 1.4em;
-    margin: 0;
-    padding: 0;
-}
-
-.starred:after {
-    content: "*";
-}
-
-header {
-    padding: 2em;
-    border-bottom: 1px solid #aaa;
-}
-
-.nightmode header {
-    border-bottom-color: #222;
-}
-
-header p {
-    color: #666;
-    margin: 0;
-    padding: 0;
-}
-
-.nightmode header p {
-    color: #888;
-}
-
-a {
-    color: inherit;
-    text-decoration: none;
-}
-
-article {
-    line-height: 1.6;
-    margin: 2em;
-}
-
-article a {
-    text-decoration: underline;
-}
-
-blockquote {
-    font-style: italic;
-}
-
-img {
-    max-width: 100%;
-    height: auto;
-}
-
-div > a:only-child img, figure > a:only-child img, p > a:only-child img,
-figure > img:only-child, div > img:only-child, p > img:only-child {
-    display: block;
-    margin: 1em auto;
-    float: none !important;
-}
-
-pre {
-    overflow: auto;
-}