Add keyboard shortcuts documentation (#2129)

There is currently no documentation which shortcuts are available to the end user, neither within the application nor the documentation published on scm-manager.org. This PR adds the missing documentation in both places and introduces a new api for developers to add documentation when using `useShortcut`. It also improves the api for conditional shortcuts significantly.

scm-ui/ui-webapp/src/shortcuts/splitKeyCombination.ts

@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+import parser from "ua-parser-js";
+
+export default function splitKeyCombination(key: string, userAgent = window.navigator.userAgent) {
+  const {
+    os: { name: osName },
+  } = parser(userAgent);
+  const isMacOS = osName === "Mac OS";
+  return key
+    .replace(/(option|alt)/g, isMacOS ? "option" : "alt")
+    .replace(/(command|meta)/g, isMacOS ? "⌘" : "meta")
+    .replace("mod", isMacOS ? "⌘" : "ctrl")
+    .split(/[+ ]/);
+}