feat: close modals with esc key (#741)

Co-authored-by: Dominik Pschenitschni <mail@celement.de>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/741
Reviewed-by: konrad <k@knt.li>
Co-authored-by: dpschen <dpschen@noreply.kolaente.de>
Co-committed-by: dpschen <dpschen@noreply.kolaente.de>

src/views/About.vue

@@ -1,7 +1,12 @@
 <template>
 	<transition name="fade">
 		<div class="modal-mask hint-modal">
-			<div @click.self="$router.back()" class="modal-container">
+			<div
+				class="modal-container"
+				@click.self="$router.back()"
+				@shortkey="$router.back()"
+				v-shortkey="['esc']"
+			>
 				<div class="modal-content">
 					<card
 						class="has-background-white has-no-shadow"