Make the Keyboard Shortcuts dialog into a settings tab (#7198)

res/css/views/dialogs/_KeyboardShortcutsDialog.scss

@@ -1,65 +0,0 @@
-/*
-Copyright 2020 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-.mx_KeyboardShortcutsDialog {
-    display: flex;
-    flex-wrap: wrap;
-    -webkit-box-orient: vertical;
-    -webkit-box-direction: normal;
-    flex-direction: column;
-    margin-bottom: -50px;
-    max-height: 1100px; // XXX: this may need adjusting when adding new shortcuts
-
-    .mx_KeyboardShortcutsDialog_category {
-        width: 33.3333%; // 3 columns
-        margin: 0 0 40px;
-
-        & > div {
-            padding-left: 5px;
-        }
-    }
-
-    h3 {
-        margin: 0 0 10px;
-    }
-
-    h5 {
-        margin: 15px 0 5px;
-        font-weight: normal;
-    }
-
-    kbd {
-        padding: 5px;
-        border-radius: 4px;
-        background-color: $header-panel-bg-color;
-        margin-right: 5px;
-        min-width: 20px;
-        text-align: center;
-        display: inline-block;
-        border: 1px solid $kbd-border-color;
-        box-shadow: 0 2px $kbd-border-color;
-        margin-bottom: 4px;
-        text-transform: capitalize;
-
-        & + kbd {
-            margin-left: 5px;
-        }
-    }
-
-    .mx_KeyboardShortcutsDialog_inline div {
-        display: inline;
-    }
-}

res/css/views/dialogs/_UserSettingsDialog.scss

@@ -37,6 +37,10 @@ limitations under the License.
     mask-image: url('$(res)/img/element-icons/settings/preference.svg');
 }
 
+.mx_UserSettingsDialog_keyboardIcon::before {
+    mask-image: url('$(res)/img/element-icons/settings/keyboard.svg');
+}
+
 .mx_UserSettingsDialog_sidebarIcon::before {
     mask-image: url('$(res)/img/element-icons/settings/sidebar.svg');
 }