Add Alt + Click hotkey for sending emotes (#408)

## Description:

Allows the player to Alt + Click to send emotes to other players or
themself in order to ease communication.
Of course, the hotkey can be something different. Alt + Click is just a
suggestion.


![image](https://github.com/user-attachments/assets/9762c4f0-f62d-4c39-ba35-468ac3f5ddaa)

## Please complete the following:

- [ x ] I have added screenshots for all UI updates
- [ x ] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [ x ] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

kanekane0448

PS: The new emoji table looks really good!

---------

Co-authored-by: kanekane0448 <no@mail.pls>

src/client/HelpModal.ts

@@ -46,6 +46,10 @@ export class HelpModal extends LitElement {
                 <td>Ctrl + left click</td>
                 <td>${translateText("help_modal.action_build")}</td>
               </tr>
+              <tr>
+                <td>Alt + left click</td>
+                <td>${translateText("help_modal.action_emote")}</td>
+              </tr>
               <tr>
                 <td>C</td>
                 <td>${translateText("help_modal.action_center")}</td>