message: Add tooltip to the add/remove keybinding buttons.
diff: @@ -53,7 +53,8 @@ type KeybindingsKeyInputState = "read" | "edit" | "conflict";
  <button
  v-if="!readOnly"
  v-on:click="deleteKey(command, keybinding)"
  - class="btn btn-microtool-danger">
  + class="btn btn-microtool-danger"
  + title="Remove keybinding">
  <i class="fas fa-times"></i>
  </button>
  </template>
  @@ -61,7 +62,8 @@ type KeybindingsKeyInputState = "read" | "edit" | "conflict";
  <button
  v-if="!readOnly && effectiveInputState(command) === 'read'"
  v-on:click="addKey(command)"
  - class="btn btn-microtool-success">
  + class="btn btn-microtool-success"
  + title="Add keybinding">
  <i class="fas fa-plus"></i>
  </button>
  